Herbicidal carbamates and thiolcarbamates
This is a division of Ser. No. 520,114 filed Nov. 1, 1974, and now U.S. Pat. No. 4,004,915 which is a division of Ser. No. 356,422 filed May 2, 1973 and now U.S. Pat. No. 3,882,160 which is a continuation-in-part of Ser. No. 312,904 filed Dec. 7, 1972 and now U.S. Pat. No. 3,823,179. 
    
    
     SUMMARY OF THE INVENTION 
     According to the present invention, it has now been discovered that certain novel carbamates and thiolcarbamates are effective and readily available herbicides. The compounds of this invention can be represented by the isomeric Formulas (1) and (2), which differ only in the position of the substitutent R 2  with a concomitant shift of the double bond. ##STR1## wherein R 1  is selected from a C 2  -C 8  alkyl substituted with 0-1 methoxy, ethoxy, methylthio, or ethylthio group; a C 3  -C 6  alkenyl; a C 3  -C 6  alkynyl; a C 4  -C 8  cycloalkyl substituted with 0-1 C 2  -C 4  alkyl, 0-2 methyl groups, 0-2 chlorine or bromine atoms, or 0-1 methoxy or ethoxy group; a C 5  -C 8  cycloalkenyl; a C 4  -C 8  cycloalkylmethyl or cycloalkenylmethyl; a C 7  -C 10  bicycloalkyl or bicycloalkenyl; a C 8  -C 11  bicycloalkylmethyl or bicycloalkenylmethyl; trimethylcyclohexyl; tetramethylcyclohexyl; and ##STR2## wherein Q is hydrogen, fluorine, chlorine, bromine, a C 1  -C 4  alkyl, a C 1  -C 2  alkoxy or alkylthio group, nitro or trifluoromethyl group; 
     Y is hydrogen, chlorine, or methyl; and 
     Z is hydrogen or chlorine; 
     R 2  is a C 1  -C 3  alkyl; 
     R 3  is hydrogen, methyl, or ethyl; 
     R 4  is a C 1  -C 4  alkyl, a C 3  -C 4  alkenyl, a C 3  -C 4  alkynyl, or methoxyl; 
     R 5  is --OR 6  or --SR 6 , 
     wherein R 6  is a C 1  -C 8  alkyl substituted with O-3 chlorine atoms or 0-1 methoxyl; and 
     X is oxygen or sulfur. 
     The compounds of this invention can be applied to the locus of weeds either preemergence or postemergence provide excellent protection against a broad spectrum of weeds. 
     DETAILED DESCRIPTION OF THE INVENTION 
     Especially highly active and, therefore, preferred compounds of the present invention are those compounds represented by the above Formulas (1) and (2), wherein 
     R 1  is alkyl of 3 through 6 carbon atoms, cycloalkyl of 5 through 8 carbon atoms, or cycloalkyl of 5 through 8 carbon atoms substituted with one methyl group; 
     R 2 , r 3  and R 4  are methyl; and 
     R 5  is OR 6 . 
     Particularly preferred within this class are those compounds of Formulas (1) and (2) where 
     R 1  is cyclopentyl, methylcyclopentyl, cyclohexyl or methylcyclohexyl; 
     X is oxygen; and 
     R 5  is methoxyl. 
     The following reaction sequence I, which illustrates the preparation of methyl N-(N-cyclohexylcarbamoyl-N&#39;,N&#39;-dimethylamidino)-N-methylcarbamate, is suitable for the preparation of most of the compounds of Formula (1) contemplated by this disclosure: ##STR3## Other compounds of Formula (1) contemplated by this disclosure can be synthesized by a reaction of appropriate alkylcyanamides with ##STR4## where R 5  has the above-defined meaning. 
     This reaction is shown below as the first step of Sequence II. 
     
         ______________________________________                                    
Sequence II                                                               
A)                                                                        
     ##STR5##                                                             
B)                                                                        
     ##STR6##                                                             
C)                                                                        
     ##STR7##                                                             
The following reaction sequence III, which illustrates the preparation of  
 methyl                                                                    
 N- 1-(3-cyclohexyl-1-methylureido)-1-dimethylaminomethylene!carbamate is  
 suitable for the preparation of the compounds of the isomeric Formula (2).
 
    
     
         ______________________________________                                    
Sequence III                                                              
 ##STR8##                                                                 
 ##STR9##                                                                 
 ##STR10##                                                                
 ##STR11##                                                                
 ##STR12##                                                                
 ##STR13##                                                                
 ##STR14##                                                                
 ##STR15##                                                                
______________________________________                                    
 
    
    
    
     These preparations are described in the following Examples, wherein all the proportions, parts, and percentages are by weight. 
     EXAMPLE 1 
     A. Synthesis of N-Methoxycarbonyl-N-Methylcyanamide 
     To a solution of 504 parts of a 50% aqueous cyanamide solution in 825 parts of water at 25° C. are added during a period of 90 minutes and at a pH of 6.9-7.1 simultaneously 572 parts of methyl chloroformate and 945 parts of a 50% aqueous sodium hydroxide solution. As the addition of the reactants progresses, the temperature of the reaction is allowed to rise to 53°-55° C. and is maintained within that range by cooling. When the addition is complete, the reaction mass is cooled to 25° C., whereupon crystallization of the sodium salt of methoxycarbonylcyanamide occurs. Dimethyl sulfate (775 parts) is then added, and agitation of the reaction mass is continued while maintaining the pH at 7-7.1 by a dropwise addition of about 25 parts of a 50% aqueous sodium hyroxide solution. After 6.5 hours, the resulting two-phase solution is repeatedly extracted with methylene chloride and the extract is dried. One half of the methylene chloride extract is then evaporated under vacuum, and the residue is distilled at 50° C./0.5 mm. There is obtained 237.6 parts of N-methoxycarbonyl-N-methylcyanamide (69.5% yield). 
     B. Synthesis of N-Methoxycarbonyl-N,N&#39;,N&#39;-Trimethylguanidine 
     A solution of 339 parts of dimethylamine hydrochloride in 500 parts of water is heated to 50° C., and the remaining one half of the above methylene chloride extract is added to it gradually, while at the same time removing the methylene chloride by distillation. The resulting two-phase mixture is then heated for approximately 20 hours at 80° C., after which time the starting N-methoxycarbonyl-N-methylcyanamide has nearly completly disappeared. The solution is then cooled to 0° C., and 336 parts of a 50% aqueous sodium hydroxide is added. Repeated extraction of the reaction solution with methylene chloride and evaporation of the methylene chloride under vacuum gives 228.6 parts of crude N-methoxycarbonyl-N,N&#39;,N&#39;-trimethylguanidine of 84.4% purity, from which the pure product is isolated by distillation at 72° C./0.5 mm. 
     C. Synthesis of Methyl N-(N-cyclohexylcarbamoyl-N&#39;,N&#39;-dimethylamidino)-N-methylcarbamate 
     To 14.8 parts of the above crude N-methoxycarbonyl-N,N&#39;,N&#39;-trimethylguanidine in 50 parts of methylene chloride is added 11.0 parts of cyclohexyl isocyanate. The solution temperature reaches the boiling point, and when the temperature has fallen to 25° C., the solvent is evaporated under vacuum to give an oil, which crystallizes when triturated with ether. Recrystallization from a mixture of carbon tetrachloride and petroleum ether gives pure methyl N-(N-cyclohexylcarbamoyl-N&#39;,N&#39;-dimethylamidino)-N-methylcarbamate, m.p. 93°-94° C. 
     Using appropriate starting materials, the following compounds can be prepared in a similar manner. 
     
                                           TABLE I                                 
__________________________________________________________________________
methyl N-(N-n-hexylcarbamoyl-N&#39;,N&#39;-dimethylamidino)-N-                    
methylcarbamate                                                           
methyl N-(N-isopropylcarbamoyl-N&#39;,N&#39;-dimethylamidino)-N-                  
methylcarbamate                                                           
methyl N- N-(4-methoxycyclohexylcarbamoyl-N&#39;,N&#39;-dimethyl-                 
amidino)!-N-methylcarbamate                                               
methyl N- N-(3,4-dimethylcyclohexylcarbamoyl-N&#39;,N&#39;-di-                    
methylamidino)!-N-methylcarbamate                                         
methyl N- N-(4-chlorophenylcarbamoyl)-N&#39;,N&#39;-                              
dimethylamidino!-N-methylcarbamate                                        
methyl N- N-(2-chlorophenylcarbamoyl)-N&#39;,N&#39;-                              
dimethylamidino!-N-methylcarbamate                                        
methyl N- N-(3-methylphenylcarbamoyl)-N&#39;,N&#39;-                              
dimethylamidino!-N-methylcarbamate                                        
                                  m.p. 145° C                      
methyl N- N-(4-methylphenylcarbamoyl)-N&#39;,N&#39;-                              
dimethylamidino!-N-methylcarbamate                                        
                                  m.p. 127° C                      
methyl N-(N-cyclopentylcarbamoyl-N&#39;,N&#39;-di-                                
methylamidino)-N-methylcarbamate                                          
methyl N-(N-cyclooctylcarbamoyl-N,N&#39;-dimethyl- -amidino)-N-methylcarbamate
methyl N- N-(3-fluorophenylcarbamoyl)-N&#39;,N&#39;-                              
dimethylamidino!-N-methylcarbamate                                        
                                  m.p. 126° C                      
methyl N- N-(4-fluorophenylcarbamoyl)-N&#39;,N&#39;-                              
dimethylamidino!-N-methylcarbamate                                        
                                  m.p. 95-97.5° C                  
methyl N-(N-n-butylcarbamoyl-N&#39;,N&#39;,-dimethyl-                             
amidino)-N-methylcarbamate                                                
methyl N-(N-n-propylcarbamoyl-N&#39;,N&#39;-dimethyl-                             
amidino)-N-methylcarbamate                                                
methyl N- N-(4-bromophenylcarbamoyl-N&#39;,N&#39;-di-                             
methylamidino)!-N-methylcarbamate m.p. 242-247° C.                 
methyl N- N-(1-decahydronaphthylcarbamoyl)-                               
N&#39;,N&#39;-dimethylamidino!-N-methylcarbamate                                  
methyl N- N-(4-fluorophenylthiocarbamoyl)-                                
                                  m.p. 132-133° C                  
N&#39;N&#39;-dimethylamidino!-N-methylcarbamate                                   
methyl N-(N-cyclohexylthiocarbamoyl-N&#39;,N&#39;-di-                             
                                  m.p. 122-123° C                  
methylamidino)-N-methylcarbamate                                          
methyl N-(N-phenylthiocarbamoyl-N&#39;,N&#39;-dimethyl-                           
                                  m.p. 155-157° C                  
amidino)-N-methylcarbamate                                                
methyl N- N-(3-fluorophenylthiocarbamoyl)-                                
                                  m.p. 121- 122° C                 
N&#39;,N&#39;-dimethylamidino!-N-methylcarbamate                                  
methyl N- N-(3,4-dichlorophenylcarbamoyl)-                                
                                  m.p. 146° C                      
N&#39;,N&#39;-dimethylamidino!-N-methylcarbamate                                  
methyl N- N-(4-methoxyphenylcarbamoyl)-                                   
N&#39;,N&#39;-dimethylamidino!-N-methylcarbamate                                  
methyl N-(N-allycarbamoyl-N&#39;,N&#39;-dimethyl-                                 
amidino)-N-methylcarbamate                                                
methyl N- N-(2-fluorophenylcarbamoyl)-N&#39;,N&#39;-dimethyl-                     
amidino!-N-methylcarbamate                                                
methyl N-(N-cyclohexylmethylcarbamoyl-N&#39;,N&#39;-dimethyl-                     
amidino)-N-methylcarbamate                                                
methyl N-(N-ethylcarbamoyl-N&#39;,N&#39;-dimethylamidino)-N- -methylcarbamate     
methyl N- N(2-hexen-1-ylcarbamoyl)-N&#39;,N&#39;-dimethyl-                        
amidino!-N-methylcarbamate                                                
methyl N-(N-propargylcarbamoyl-N&#39;,N&#39;-dimethylamidino)-                    
N-methylcarbamate                                                         
methyl N- N-(2-hexyn-1-ylcarbamoyl)-N&#39;,N&#39;-dimethylamidino!-               
N-methylcarbamate                                                         
methyl N- N-(1,3-dimethylbutylcarbamoyl)-N&#39;,N&#39;-dimethyl-                  
amidino!-N-methylcarbamate                                                
methyl N- N-(1-ethylpropylcarbamoyl)-N&#39;,N&#39;-dimethylamidino!-              
-N-methylcarbamate                                                        
methyl N- N-(1-isopropyl-2-methylpropylcarbamoyl)-N&#39;,N&#39;-                  
dimethylamidino!-N-methylcarbamate                                        
methyl N- N-(1,2,2-trimethylpropylcarbamoyl)-N&#39;,N&#39;-                       
dimethylamidino!-N-methylcarbamate                                        
methyl N-(N-n-pentylcarbamoyl-N,N&#39;-dimethylamidino)-N-methyl-             
carbamate                                                                 
methyl N- N-(1-methylbutylcarbamoyl)-N&#39;,N&#39;-dimethylamidino!-              
N-methylcarbamate                                                         
methyl N- N-(3-trifluoromethylphenylcarbamoyl)-N&#39;,N&#39;-dimethyl-            
amidino!-N-methylcarbamate                                                
methyl N-(N-n-octylcarbamoyl-N&#39;,N&#39;-dimethylamidino)-N-methyl-             
carbamate                                                                 
methyl N- N-(2-methylcyclohexylcarbamoyl)-N&#39;,N&#39;-dimethylamidino!-         
N-methylcarbamate                                                         
methyl N- (N-(3-methylcyclohexylcarbamoyl)-N&#39;,N&#39;-dimethylamidino!-        
N-methylcarbamate                                                         
methyl N-(N-cycloheptylcarbamoyl-N&#39;,N&#39;-dimethylamidino)-                  
N-methylcarbamate                                                         
methyl N-(N-cyclohexylmethylcarbamoyl-N&#39;,N&#39;-dimethylamidino)-             
N-methylcarbamate                                                         
methyl N-∂N-(2-cyclohexenylcarbamoyl)-N&#39;,N&#39;-dimethylamidino!-
1                                                                         
N-methylcarbamate                                                         
methyl N- N-(3-cyclohexenylcarbamoyl)-N&#39;,N&#39;-dimethyl-                     
amidino!-N-methylcarbamate                                                
methyl N-(N-cyclohexenylmethylcarbamoyl-N&#39;,N&#39;-dimethyl-                   
amidino)-N-methylcarbamate                                                
methyl N- N-(2-cyclooctenylcarbamoyl)-N&#39;,N&#39;-dimethyl-                     
amidino!-N-methylcarbamate                                                
methyl N-(N-norbornylcarbamoyl-N&#39;,N&#39;-dimethylamidino)-                    
N-methylcarbamate                                                         
methyl N-(N-norbornylmethylcarbamoyl-N&#39;,N&#39;-dimethylamidino)-              
N-methylcarbamate                                                         
methyl N-(N-norbornenylcarbamoyl)-N&#39;,N&#39;-dimethylamidino)-                 
N-methylcarbamate                                                         
methyl N-(N-norbornenylmethylcarbamoyl-N&#39;,N&#39;-dimethyl-                    
amidion)-N-methylcarbamate                                                
methyl N-∂N(2,3,5-trimethylcyclohexylcarbamoyl)-N&#39;,N&#39;-       
dimethylamidino!-N-methylcarbamate                                        
methyl N- N-(2,3,5,6-tetramethylcyclohexylcarbamoyl)-N&#39;,N&#39;-               
dimethylamidino!-N-methylcarbamate                                        
methyl N- N-(3,3,5,5-tetramethylcyclohexylcarbamoyl)-N&#39;,N&#39;-               
dimethylamidino!-N-methylcarbamate                                        
methyl N- N-(2-chlorocyclohexylcarbamoyl)-N&#39;,N&#39;-dimethyl-                 
amidino!-N-methylcarbamate                                                
methyl N- N-(1-methylcyclopentylcarbamoyl)-N&#39;,N&#39;-dimethyl-                
amidino!-N-methylcarbamate                                                
methyl N- (-(2,3-dichlorocyclohexylcarbamoyl)-N&#39;,N&#39;-dimethyl-             
amidino!-N-methylcarbamate                                                
methyl N- N-p-methoxycyclohexylcarbamoyl)-N&#39;,N&#39;-dimethyl-                 
amidino!-N-methylcarbamate                                                
methyl N- N-(4-ethoxycyclohexylcarbamoyl)-N&#39;,N&#39;-dimethyl-                 
amidino!-N-methylcarbamate                                                
methyl N- N-(2-ethylcyclohexylcarbamoyl)-N&#39;,N&#39;-dimethyl-                  
-amidion!-N-methylcarbamate                                               
methyl N- N-(4-tert-butylcyclohexylcarbamoyl)-N&#39;,N&#39;-dimethyl-             
amidino!-N-methylcarbamate                                                
methyl N-(N-cyclohexylthiocarbamoyl-N&#39;,N&#39;-dimethylamidino)-               
N-methylcarbamate                                                         
methyl N-(N-cyclopentylthiocarbamoyl-N&#39;,N&#39;-dimethylamidino)-              
N-methylcarbamate                                                         
methyl N- N-(2-methylcyclohexylthiocarbamoyl)-N&#39;,N&#39;-di-                   
methylamidino!  -N-methylcarbamate                                        
methyl N-(N-cyclooctylcarbamoyl-N&#39;-butylamidino)-N-methyl-                
carbamate                                                                 
methyl N-(N-cyclopentylcarbamoyl-N&#39;-allylamidino)-N-methyl-               
carbamate                                                                 
methyl N-(N-neopentylcarbamoyl-N&#39;,N&#39;-dimethylamidino)-N-                  
methylcarbamate                                                           
ethyl N-(N-cyclohexylcarbamoyl-N&#39;,N&#39;-dimethylamidiono)-N-                 
methylcarbamate                                                           
ethyl N-(N-propargylcarbamoyl-N&#39;,N&#39;-dimethylamidino)-N-                   
methylcarbamate                                                           
ethyl N-(N-hexyn-2-ylcarbamoyl-N&#39;,N&#39;-dimethylamidino)-N-                  
methylcarbamate                                                           
ethyl N- N-allycarbamoyl-N&#39;-(2-methylallyl)amidino!-N-                    
methylcarbamate                                                           
ethyl N-(N-buten-2-ylcarbamoyl-N&#39;,N&#39;-dimethylamidino)-                    
N-methylcarbamate                                                         
ethyl N- N-(2-cyclopentenylcarbamoyl)-N&#39;,N&#39;-dimethyl-                     
amidino!-N-methylcarbamate                                                
butyl N-(N-cyclohexylcarbamoyl-N&#39;,N&#39;-dimethylamidino)-                    
N-methylcarbamate                                                         
octyl N-(N-cyclohexylcarbamoyl-N&#39;,N&#39;-dimethylamidino)-N-/                 
-methylcarbamate                                                          
octyl N- N-(2,6-dimethylcyclohexylcarbamoyl)-N&#39;,N&#39;-dimethyl-              
amidino!-N-methylcarbamate                                                
octyl N- N-(2-norbornylcarbamoyl)-N&#39;,N&#39;-dimethylamidino!-N-               
methylcarbamate                                                           
methyl N- N-(2-methylthiopropylcarbamoyl)-N&#39;,N&#39;-dimethyl-                 
amidino!-N-ethylcarbamate                                                 
methyl N- N-(1-methylcyclohexylcarbamoyl)-N&#39;,N&#39;-dimethyl-                 
amidino!-N-ethylcarbamate                                                 
methyl N-(N-cyclohexylcarbamoyl-N&#39;,N&#39;-dimethylmidino)-                    
N-ethylcarbamate                                                          
methyl N- N-(p-methylthiophenylcarbamoyl)-N&#39;-methylamidino!-              
N-methylcarbamate                                                         
methyl N-(N-cyclohexylcarbamoyl-N&#39;-methylamidino)-N-methyl-               
carbamate                                                                 
methyl N- N-(3-chloro-4-butylphenylcarbamoyl)-N&#39;-propargyl-               
amidion!-N-methylcarbamate                                                
methyl N- N-(4-ethoxyphenylcarbamoyl)-N&#39;-butyn-2-yl-                      
amidino!-N-methylcarbamate                                                
2,2,2-trichloroethyl N- N-(p-ethylthiophenylcarbamoyl)-                   
N&#39;,N&#39;-dimethylamidino!-N-methylcarbamate                                  
2-methoxyethyl N-(N-cyclobutylcarbamoyl-N&#39;,N&#39;-dimethyl-                   
amidino)-N-methylcarbamate                                                
methyl N-(N-cyclopropylmethylcarbamoyl-N&#39; 40 ,N&#39;-dimethyl-                
amidion)-N-methylcarbamate                                                
;methyl N-(N-cycloheptylmethylcarbamoyl-N&#39;,N&#39;-diethyl-                    
amidino)-N-methylcarbamate                                                
methyl N-(N-cyclopropen-2-ylmethylcarbamoyl-N&#39;,N&#39;-di-                     
methylamidino)-N-methylcarbamate                                          
me;thyl N-(N-cyclohepten-4-ylmethylcarbamoyl-N&#39;,N&#39;-di-                    
methylamidino)-N-methylcarbamate                                          
methyl N- N-(1-decahydronaphthylmethylcarbamoyl)-N&#39;,N&#39;-                   
dimethylamidino!-N-methylcarbamate                                        
methyl N- N-(1-decahydronaphthen-2-ylmethylcarbamoyl)-                    
N&#39;,N&#39;-dimethylamidino!-N-methylcarbamate                                  
methyl N-(N-cyclohexylcarbamoyl-N&#39;-butylamidino)-N-                       
methylcarbamate                                                           
methyl N- N-(3-chloro-4-methylthiophenylcarbamoyl)-N&#39;-(2-                 
methylallyl)amidino!-N-methylcarbamate                                    
methyl N-(N-cyclohexylcarbamoyl-N&#39;-methoxy-N&#39;-methyl-                     
amidino)-N-methyl carbamate                                               
methyl N-(N-cyclohexylcarbamoyl-N&#39;-butyl-N&#39;-methylamidino)-               
N-methylcarbamate                                                         
methyl N- N-(2-decahydronaphthylcarbamoyl)-N&#39;,N&#39;-dimethyl-                
amidino!-N-methylcarbamate                                                
methyl N- N-(2-norbornylcarbamoyl)-N&#39;,N&#39;-dimethylamidino!-                
N-methylcrbamate                                                          
methyl N-∂N-(2-norbornylcarbamoyl)-N&#39;-methylamidino!-N-methyl
carbamate                                                                 
methyl N- N-(p-tolycarbamoyl)-N&#39;,N&#39;-dimethylamidino!-N-methyl-            
arbamate                                                                  
methyl N-(N-cyclohexylcarbamoyl-N&#39;,N&#39;-dimethylamidino)-N-methyl-          
thiolcarbamate                                                            
methyl N-(N-cyclopentylcarbamoyl-N&#39;,N&#39;-dimethylamidino)-N-methyl-         
thiolcarbamate                                                            
methyl N- N-(2-methylcyclohexyl)-N&#39;,N&#39;-dimethylamidino!-N-methyl-         
thiolcarbamate                                                            
methyl N- N-(3-methylcyclohexyl)-N&#39;,N&#39;-dimethylamidino!-N-methyl-         
thiolcarbamate                                                            
methyl N-(N-cycloheptylcarbamoyl-N&#39;,N&#39;-dimethylamidino)-N-methyl-         
thiolcarbamate                                                            
methyl N-(N-cyclooctylcarbamoyl-N&#39;,N&#39;-dimethylamidino)-N-methyl-          
thiolcarbamate                                                            
methyl N-(N-cyclohexylmethylcarbamoyl-N&#39;,N&#39;-dimethylamidino)-N-           
methylthiocrbamate                                                        
methyl N-(N-norbornylcarbamoyl-N,N&#39;-dimethylamidino)-N-methyl-            
thiolcarbamate                                                            
methyl N-(N-cyclohexen-2-ylcarbamoyl-N&#39;,N&#39;-dimethylamidino)-N-            
methylthiolcarbamate                                                      
methyl N-(N-phenylcarbamoyl-N&#39;,N&#39;-dimethylamidino)-N-methyl-              
thiolcarbamate                                                            
methyl N- N-(3,4-dichlorophenylcarbamoyl)-N&#39;,N&#39;-dimethylamidino!-         
N-thiolcarbamate                                                          
__________________________________________________________________________
 
    
     EXAMPLE 2 
     A. Synthesis of 1,1-Dimethyl-2-methyl-2-thio-pseudourea 
     Methyl mercaptan (27 parts) and concentrated sulfuric acid are added with good agitation to a solution of 35 parts of dimethylcyanamide in 150 parts of water. The methyl mercaptan addition requires 40 minutes. The sulfuric acid is added on demand to maintain a pH of 9.5 ± 0.2.  The acid addition is stopped when the pH remains constant at 9.5 without further adjustment. This requires an additional 35 minutes. 
     The temperature is maintained at 25° ± 2° C by external cooling. Loss of mercaptan from the system is prevented by the use of a dry ice/acetone condenser. 
     When the above reaction is complete, the pH is adjusted to 5.3 and 20 mls of distillate is removed at 18 mm Hg by heating the pot to 33° C. 
     B. Synthesis of Methyl N-(1-Dimethylamino-1-methylthiomethylene)carbamate 
     Methylene chloride (174 parts) is now added to the above pot residue and 48.9 parts of methyl chloroformate is added during 112 minutes at 5° ± 5° C while 50% aqueous caustic is simultaneously added on demand with good agitation at a rate such that the pH is maintained at 9.5 ± 0.2. The caustic addition is continued at 10° C until the pH remains constant. This requires about 4 more hours. 
     The lower methylene chloride layer is removed, the pH adjusted to 11.0 with 50% caustic, and the aqueous phase extracted twice with 150 mls of methylene chloride. The combined extracts are evaporated to constant weight on a rotary evaporator to give 78.5 parts of crude methyl N-(1-dimethylamino-1-methylthiomethylene)carbamate as an oil which is purified by vacuum fractionation to give 59.8 parts of product, b.p. 103° C at 0.4 mm Hg. 
     C. Synthesis of Methyl N-(1-Dimethylamino-1-methylaminomethylene)carbamate 
     The above distillate is added to a solution of 28.6 parts of monomethylamine in 423 parts of toluene and stirred in a closed system for 24 hours. The reaction mass is then evaporated to constant weight on a rotary evaporator to give 55 parts of an oil which solidifies on standing overnight, m.p. 80°-85° C. Recrystallization from toluene-heptane gives 41.0 parts of methyl N-(1-dimethylamino-1-methylaminomethylene) carbamate as a pure white crystalline material, m.p. 87°-89° C. 
     D. Synthesis of Methyl N- 1-(3-Cyclohexyl-1-methylureido)-1-dimethylaminomethylene!carbamate 
     The above product is dissolved in a solution of 32.2 parts of cyclohexyl isocyanate in 510 parts of 1,2-dichloroethane and heated under reflux for 2 hours. The reaction mass is cooled to room temperature, and 586 parts of water is added. The pH of the resulting aqueous phase is adjusted to approximately 2 with conc. hydrochloric acid. The aqueous phase is separated, 1020 parts of 1,2-dichloroethane added to it, and enough 50% caustic is added to adjust the pH of the aqueous phase to 10 to 11. The mixture is shaken and the 1,2-dichloroethane layer evaporated to constant weight on a rotary evaporator to give 43.0 gms of oil, which crystallizes on standing to give an impure solid, m.p. 60°-75°. Recrystallization from toluene-heptane gives 16.3 parts of methyl N- 1-(3-cyclohexyl-1-methylureido)-1-dimethylaminomethylene!carbamate as pure white crystals, m.p. 81°-82° C. 
     Using the appropriate starting materials, the following compounds can be prepared in a similar manner. 
     methyl N- 1-(3 -n-pentyl-1-methylureido)-1-dimethylaminomethylene!carbamate 
     methyl N- 1-(3-cyclohexylmethyl-1-methylureido)-1-dimethylaminomethylene!carbamat 
     methyl N- 1-(3 -n-propyl-1-methylureido)-1-dimethylaminomethylene!carbamate 
     methyl N- 1-(3 -n-butyl-1-methylureido)-1-dimethylaminomethylene!carbamate 
     methyl N- 1-(3 -n-hexyl-1-methylureido)-1-dimethylaminomethylene!carbamate 
     methyl N- 1-(3 -n-octyl-1-methylureido)-1-dimethylaminomethylene!carbamate 
     methyl N-{1- 3-(1,3-dimethylbutyl)-1-methylureido!-1-dimethylaminomethylene}carbamate 
     methyl N-{1- 3-(1-ethylpropyl)-1-methylureido!-1-dimethylaminomethylene}carbamate 
     methyl N-{1- 3-(1-isopropyl-2-methylpropyl)-1-methylureido!-1-dimethylaminomethylene}carbamate 
     methyl N-{1- 3-(1,2,2-trimethylpropyl)-1-methylureido!-1-dimethylaminomethylene}carbamate 
     methyl N- 1-(3-neopentyl-1-methylureido)-1-dimethylaminomethylene!carbamate 
     methyl N-{1- 3-(1-methylbutyl)-1-methylureido!-1-dimethylaminomethylene}carbamate 
     methyl N-{1- 3-(3-trifluoromethylphenyl)-1-methylureido!-1-dimethylaminomethylene}carbamate 
     methyl N- 1-(3-ethyl-1-isopropylureido)-1-diethylaminomethylene!carbamate 
     methyl N- 1-(3-butyl-1-propylureido)-1-methyl-1-propylaminomethylene!carbamate 
     methyl N- 1-(3-octyl-1-methylureido)-1-allylaminomethylene!carbamate 
     methyl N-{1- 3-(2-norbornyl)-1methylureido!-1-dimethylaminomethylene}carbamate 
     methyl N- 1-(3-phenyl-1-methylureido)-1-dimethylaminomethylene!carbamate 
     methyl N-{1- 3 -(p-chlorophenyl)-1-methylureido!-1-dimethylaminomethylene}carbamate 
     methyl N-{1- 3-(3,4-dichlorophenyl)-1-methylureido!-1-dimethylaminomethylene}carbamate 
     ethyl N- 1-(3-cyclohexyl-1-methylureido)-1-dimethylaminomethylene!carbamate 
     ethyl N- 1-(3-cyclooctyl-1-methylureido)-1-dimethylaminomethylene!carbamate 
     ethyl N- 1-(3-phenyl-1-methylureido)-1-dimethylaminomethylene!carbamate 
     ethyl N-{1- 3-(m-tolyl)-1-methylureido!-1-dimethylaminomethylene}carbamate 
     octyl N- 1-(3-cyclohexyl-1-methylureido)-1-dimethylaminomethylene!carbamate 
     methyl N-{1- 3-(2-ethoxybutyl)-1-methylureido!-1-dimethylaminomethylene}carbamate 
     methyl N-{1- 3-(2-methylthiobutyl)-1-methylureido!-1-dimethylaminomethylene}carbamate 
     ethyl N-{1- 3-(2-ethylthiopropyl)-1-methylureido!-1-dimethylaminomethylene}carbamate 
     hexyl N-{1-(3-cyclohexyl-1-methylureido)-1-dimethylaminomethylene!carbamate 
     hexyl N- 1-(3-cyclopentyl-1-methylureido)-1-dimethylaminomethylene!carbamate 
     hexyl N- 1-(3-phenyl-1-methylureido)-1-dimethylaminomethylene!carbamate 
     isopropyl N- 1-(3-cyclohexyl-1-methylureido)-1-dimethylaminomethylene!carbamate 
     isopropyl N- 1-(3-norbornyl-1-methylureido)-1-dimethylaminomethylene!carbamate 
     isopropyl N-}1- 3 -(o-fluorophenyl)-1-methylureido!-1-dimethylaminomethylene}carbamate 
     isopropyl N-{1- 3-(2-propenyl)-1-methylureido!-1-dimethylaminomethylene}carbamate 
     methyl N-{1- 3-(3-methoxypropyl)-1-methylureido!-1-dimethylaminomethylene}carbamate 
     methyl N-{1- 3-(2-chlorocyclohexyl)-1-methylureido!-1-dimethylaminomethylene}carbamate 
     methyl N-{1- 3-(2,3-dichlorocyclohexyl)-1-methylureido!-1-dimethylaminomethylene}carbamate 
     methyl N-{1- 3-(2-bromocyclohexyl)-1-methylureido!-1-dimethylaminomethylene}carbamate 
     methyl N-{1- 3-(2-methylcyclohexyl)-1-methylureido!-1-dimethylaminomethylene}carbamate 
     methyl N-{1- 3-(2,6-dimethylcyclohexyl)-1-methylureido!-1-dimethylaminomethylene}carbamate 
     methyl N-{1- 3-(2-butylcyclopentyl)-1-methylureido!-1-dimethylaminomethylene}carbamate 
     methyl N-{1- 3-(2-norbornyl)-1-methylureido!-1-diethylaminomethylene}carbamate 
     methyl N-{1- 3-(cyclohexen-2-yl)-1-methylureido!-1-dimethylaminomethylene}carbamate 
     methyl N-{1- 3-(cyclopenten-2-yl)-1-methylureido!-1-dimethylaminomethylene}carbamate 
     ethyl N- 1-(3-norbornyl-1-methylureido)-1-dimethylaminomethylene!carbamate 
     isopropyl N- 1-(3-norbornyl-1-methylureido)-1-dimethylaminomethylene!carbamate 
     methyl N-{1- 3-(4-isopropylcyclohexyl)-1-methylureido!-1-dimethylaminomethylene}carbamate 
     ethyl N-{1- 3 -(p-tolyl)-1-methylureido!-1-dimethylaminomethylene}carbamate 
     ethyl N-{1- 3 -(m-nitrophenyl)-1-methylureido!-1-dimethylaminomethylene}carbamate 
     ethyl N-{1- 3-(3-chloro-4-isopropylphenyl)-1-methylureido!-1-dimethylaminomethylene}carbamate 
     ethyl N-{1- 3-(3-chloro-4-nitrophenyl)-1-methylureido!-1-dimethylaminomethylene}carbamate 
     ethyl N-{1- 3 -(p-propylphenyl)-1-methylureido!-1-dimethylaminomethylene}carbamate 
     methyl N- 1-(3-cyclohexyl-1-methylureido)-1-dimethylaminomethylene!thiolcarbamate 
     methyl N- 1-(3-cycloheptyl-1-methylureido)-1-dimethylaminomethylene!thiolcarbamate 
     methyl N- 1-(3-cyclopentyl-1-methylureido)-1-dimethylaminomethylene!thiolcarbamate 
     methyl N-{1- 3-(2-methylcyclohexyl)-1-methylureido!-1-dimethylaminomethylene}thiolcarbamate 
     methyl N- 1-(3-phenyl-1-methylureido)-1-dimethylaminomethylene!thiolcarbamate 
     methyl N-{1- 3-(3,4-dichlorophenyl)-1-methylureido!-1-dimethylaminomethylene}thiolcarbamate 
     methyl N-{1- 3-(2,4,5-trichlorophenyl)-1-methylureido!-1-dimethylaminomethylene}thiolcarbamate 
     methyl N- 1-(3-norbornyl-1-methylureido)-1-dimethylaminomethylene!thiolcarbamate 
     methyl N- 1-(3-norbornenyl-1-methylureido)-1-dimethylaminomethylene!thiolcarbamate 
     methyl N-{1- 3-(cyclohexen-2-yl)-1-methylureido!-1-dimethylaminomethylene}thiolcarbamate 
     ethyl N- 1-(3-cyclohexyl-1-methylureido)-1-dimethylaminomethylene!thiolcarbamate 
     isopropyl N- 1-(3-cyclohexyl-1-methylureido)-1-dimethylaminomethylene!thiolcarbamate 
     octyl N- 1-(3-cyclohexyl-1-methylureido)-1-dimethylaminomethylene!thiolcarbamate 
     methyl N- 1-(3-cyclohexyl-1-methylureido)-1-(N-methyl-N-ethylaminomethylene)!carbamate 
     methyl N- 1-(3-cyclohexyl-1-methylureido)-1-(N-methyl-N-butylaminomethylene)!carbamate 
     methyl N- 1-(3-cyclohexyl-1-methylureido)-1-(N-methyl-N-allylaminomethylene)!carbamate 
     methyl N- 1-(3-cyclohexyl-1-methylureido)-1-(N-methyl-N-propargylaminomethylene)!carbamate 
     methyl N-{1- 3 -(p-methylthiophenyl)-1-methylureido!-1-dimethylaminomethylene}carbamate 
     methyl N-{1- 3 -(p-methoxyphenyl)-1-methylureido!-1-dimethylaminomethylene}carbamate 
     methyl N-{1- 3-(2,3,5,6-tetramethylcyclohexyl)-1-methylureido!-1-dimethylaminomethylene}carbamate 
     The compounds of Formulas (1) and (2) can be used wherever general weed control is desired, for example, in industrial areas, railroad rights-of-way, and around highway structures. 
     The precise amount of active material to be used in any given situation will vary according to the plant species and soil involved, the formulation used, the mode of application, prevailng weather conditions, foliage density, length of residual activity desired, and like factors. It is, therefore, not possible to recommend a rate of application suitable for all situations. Broadly speaking, the compounds of the invention are used at levels of about 1 to about 25 kilograms per hectare. 
     The compounds of the present invention may be combined in any other herbicide and are particularly useful in combination with 3-sec-butyl-5-bromo-6-methyluracil (bromacil), 3-(3,4-dichlorophenyl)-1,1-dimethylurea (diuron), 1,1&#39;-dimethyl-4,4&#39;-bipyridinium salt (paraquat), 1,1-dimethyl-3-(3-N-tert-butylcarbamoyloxyphenyl)urea, 4-amino-6 -tert-butyl-3-methylthlo-as-triazin- 5(4H)-one, and s-triazines such as 2-chloro-4-ethylamino-6-isopropylamino-s-triazine, for controlling a broad spectrum of weeds. 
     Many of the compounds of this invention possess unusually high water solubility, up to several percent. This offers an advantage in, for instance, control of brush and other deep-rooted, perennial weeds. An example of a highly water-soluble compound of this inventon is methyl N-(N-cyclohexylcarbamoyl-N&#39;,N&#39;-dimethylamidino)-N-methylcarbamate; this compound exhibits a solubility in water of about 22.7% at 25° C. 
     The herbicidal activity of the compounds of this invention was discovered in a greenhouse test. In this test seeds of crabgrass (Digitaria spp.), barnyardgrass (Echinochloa crusgalli), sorghum (Sorghum vulgare), wild oats (Avena fatua), Cassia tora, morningglory (Ipomoea spp.), radish (Raphanus spp.), marigold (Tagetes spp.), dock (Rumex crispus), and nutsedge (Cyperus rotundus) tubers were planted in a growth medium and treated preemergence at two rates (11 and 2.2 kg. per hectare) with the chemical dissolved in a nonphytotoxic solvent. Johnsongrass (Sorghum halepense) having four leaves, crabgrass and barnyardgrass with three leaves and nutsedge from tubers with two leaves were treated postemergence at 11 kg per hectare, and bush beans with the third trifoliate leaf expanding and sorghum with four leaves were treated postemergence at 2.2 kg per hectare. Treated plants and controls were maintained in the greenhouse for 16 days, then all species were compared to controls and visually rated for responses to treatment. A quantitative rating was made on a scale of 0 to 10. A qualitative rating (type of injury) was also made. 
     The results obtained for methyl N-(N-cyclohexylcarbamoyl-N&#39;,N&#39;-dimethylamidino)-N-methylcarbamate (I) and methyl N- 1-(3-cyclohexyl-1-methylureido)-1-dimethylaminomethylene!carbamate (II) are shown in Table III, below, wherein 0 indicates no effect and 10 means that all plants are affected, i.e., complete kill. C indicates chlorosisnecrosis and G growth retardation. 
     
                                           TABLE III                               
__________________________________________________________________________
       POSTEMERGENCE  PREEMERGENCE                                        
    kg.                                                                   
    per    John-   Barn-   Barn-             Morn-                        
Com-                                                                      
    hec- Nut-                                                             
       son-                                                               
           Crab-                                                          
               yard-                                                      
                   Crab-                                                  
                       yard-                                              
                           Sor-                                           
                               Wild                                       
                                   Nut-                                   
                                      Cas-                                
                                          ing                             
                                             Mus-                         
                                                 Rad-                     
                                                    Mari-                 
pound                                                                     
    tare                                                                  
       sedge                                                              
           grass                                                          
               grass                                                      
                   grass                                                  
                       grass                                              
                           grass                                          
                               ghum                                       
                                   Oats                                   
                                      sedge                               
                                          sia                             
                                             glory                        
                                                 tard                     
                                                    ish                   
                                                       gold               
                                                           Dock           
__________________________________________________________________________
I   11 9C  10C 10C 10C 10C 10C 10C 10C                                    
                                      4c  10C                             
                                             10C 10C                      
                                                    10C                   
                                                       10C 10C            
    2.2                10C 10C 10C 10C                                    
                                      3C  10C                             
                                             10C 10C                      
                                                    10C                   
                                                       10C 10C            
II  2.2                                                                   
        0   8C  8C  7C 9C  10C  9C 10C                                    
                                      0   10C                             
                                             10C 10C                      
                                                    10C                   
                                                       10C 10C            
    0.4                 9C 10C  4G  6C                                    
                                      0   10C                             
                                             10C 10C                      
                                                    10C                   
                                                       10C 10C            
__________________________________________________________________________
 
    
     Useful formulations of the compounds of Formulas (1) and (2) can be prepared in conventional ways. They include dusts, granules, pellets, solutions, suspensions, emulsions, wettable powders, emulsifiable concentrates and the like. Many of these may be applied directly. Sprayable formulations can be extended in suitable media and used at spray volumes of from a few pints to several hundred gallons per acre. High strength compositions are primarily used as intermediates for further formulation. The formulations, broadly, contain about 1% to 99% by weight of at least one compound of Formulas (1) and (2) and either about 0.1% to 15% of a surfactant or about 1% to 99% of a solid or liquid carrier or both. More specifically, the formulations will contain these ingredients in the following approximate proportions: 
     
         ______________________________________                                    
           Percent by Weight                                              
           Active                                                         
           Ingredient                                                     
                    Carrier  Surfactant                                   
______________________________________                                    
Wettable &amp; Water-                                                         
Soluble Powders                                                           
             20-95      0-80     0-10                                     
Oil Suspensions,                                                          
Emulsions, Solu-                                                          
tions (including                                                          
Emulsifiable Con-                                                         
centrates)   5-50       40-95    0-15                                     
Dusts        1-25       70-99    0-5                                      
Granules and                                                              
Pellets      1-95       5-99     0-15                                     
High Strength                                                             
Compositions 90-99      0-10     0-2                                      
______________________________________                                    
 
    
     Lower or higher levels of active ingredient can, of course, be present depending on the intended use and the physical properties of the compound. Higher ratios of surfactant to active ingredient are sometimes desirable. 
     Typical solid carriers are described in Watkins et al., &#34;Handbook of Insecticide Dust Diluents and carrier,&#34;  2nd. Edn., Dorland Books, Caldwell, N.J., 1955. Less common carriers include sugars and inorganic salts. The more absorptive carriers are preferred for wettable powders and the denser one for dusts. Typical liquid carriers are described in Marsden, &#34;Solvents Guide,&#34;  2nd. Edn., Interscience, New York, 1950. Solubility under 0.1% is preferred for suspension concentrates; solution concentrates are preferably stable against phase separation at 0° C. &#34;McCutcheon&#39;s Detergents and Emulsifiers Annual,&#34;  Allured Publ. Corp., Ridgewood, N.J., as well as Sisely and Wood, &#34;Encyclopedia of Surface Active Agents,&#34; Chemical Pbl. Co., Inc., New York, 1964, list surfactants and recommended uses. All formulations can contain minor amounts of additives to reduce foam, caking, corrosion, microbiological growth, etc. Preferably, ingredients should be approved by the U.S. Environmental Protection Agency for the intended use. 
     The methods of making such compositions are well known. Solutions are prepared by simply mixing the ingredients. Fine solid compositions are made by blending and, usually, grinding as in a hammer or fluid energy mill. Suspensions are prepared by wet milling (see, for example, Littler, U.S. Pat. No. 3,060,084). Granules and pellets may be made by spraying the active material upon preformed granular carriers or by agglomeration techniques; see J. E. Browning, &#34;Agglomeration,&#34; Chemical Engineering, Dec. 4, 1967, pp. 147ff. and &#34;Perry&#39;s Chemical Engineer&#39;s Handbook,&#34; 4th. Edn., McGraw-Hill, N.Y., 1963, pp. 8-59ff. 
     For further information regarding the art of formulation, see for example: 
     H. m. loux, U.S. Pat. No. 3,235,361. 
     R. w. luckenbaugh, U.S. Pat. No. 3,309,192, 
     H. gysin and E. Knusli, U.S. Pat. No. 2,891,855. 
     G. c. klingman, &#34;Weed Control as a Science&#34;, John Wiley &amp; Sons, Inc., New York, 1961, pp. 81-96. 
     J. d. fryer and S. A. Evans, &#34;Weed Control Handbook&#34;, 5th Edn. Blackwell Scientific Publications, Oxford, 1968, pp. 101-103. 
     Typical formulations of compounds of the present invention are shown below: 
     
         ______________________________________                                    
A.    Wettable Powder                                                     
______________________________________                                    
Methyl N-(N-cyclohexylcarbamoyl-N&#39;,N&#39;-                                    
dimethylamidino)-N-methylcarbamate                                        
                             40%                                          
Dioctyl sodium sulfosuccinate                                             
                             1.5%                                         
Sodium ligninsulfonate       3%                                           
Low viscosity methyl cellulose                                            
                             1.5%                                         
Attapulgite                  54%                                          
______________________________________                                    
 
    
     The ingredients are thoroughly blended, passed through an air mill, to produce an average particle size under 15 microns, reblended, and sifted through a U.S.S. No. 50 sieve (0.3 mm opening) before packaging. 
     
         ______________________________________                                    
B.    Wettable Powder                                                     
______________________________________                                    
Methyl N- 1-(3-cyclohexyl-1-methylureido)-                                
                             70%                                          
1-dimethylaminomethylene!carbamate                                        
Sodium alkylnaphthalenesulfonate  2%                                      
Sodium N-methyl-N-oleoyltaurate                                           
                              2%                                          
Diatomaceous earth           26%                                          
______________________________________                                    
 
    
     The ingredients are blended and ground in a hammer mill so that only a few percent of the active exceeds 250 microns (U.S.S. #60 sieve) in size. After milling, the powder is reblended and sifted through a U.S.S. No. 50 sieve (0.3 mm opening) before packaging. 
     
         ______________________________________                                    
C.     Water Soluble powder                                               
______________________________________                                    
Methyl N-(N-cyclohexylcarbamoyl-N&#39;,N&#39;-                                    
                            91.0%                                         
dimethylamidino)-N-methylcarbamate                                        
Sodium alkylnaphthalenesulfonate 0.5%                                     
Magnesium sulfate heptahydrate                                            
                            7.8%                                          
Synthetic fine silica       0.7%                                          
______________________________________                                    
 
    
     The ingredients are blended and passed through a U.S.S. #40 sieve so that the particles do not exceed 420 microns in size. When added to water with stirring, the coarse powder initially disperses and then the active ingredient dissolves so that no further stirring is needed during application. 
     
         ______________________________________                                    
D.                                                                        
______________________________________                                    
 Oil Suspension                                                           
Methyl N-∂N-(3-methylphenylcarbamoyl-                        
                            25%                                           
N&#39;,N&#39;-dimethylamidino!-N-methyl- -carbamate                               
Polyoxyethylene sorbitol hexaoleate                                       
                             5%                                           
Highly aliphatic hydrocarbon oil                                          
                            70%                                           
______________________________________                                    
 
    
     The ingredients are ground together in a sand mill until the solid particles have been reduced to under about 5 microns. The resulting thick suspension may be applied directly, but preferably after being extended with oils or emulsified in water. 
     
         ______________________________________                                    
E.                                                                        
______________________________________                                    
 Extruded Pellet                                                          
Methyl N-(N-phenylthiocarbamoyl-N&#39;,N&#39;-                                    
                            25%                                           
dimethylamidino)-N-methylcarbamate                                        
Anhydrous sodium sulfate    10%                                           
Crude calcium ligninsulfonate                                             
                             5%                                           
Sodium alkylnaphthalenesulfonate                                          
                             1%                                           
Calcium/magnesium bentonite 59%                                           
______________________________________                                    
 
    
     The ingredients are blended, hammer milled and then moistened with about 12% water. The mixture is extruded as cylinders about 3 mm diameter which are cut to produce pellets about 3 mm long. These may be used directly after drying, or the dried pellets may be crushed to pass a U.S.S. No. 20 sieve (0.84 mm openings). The granules held on a U.S.S. No. 40 sieve (0.42 mm openings) may be packaged for use and the fines recycled. 
     In the following composition claims, the expression &#34;consisting essentially of&#34; means that, in addition to the components recited in those claims, other components also may be present, provided they do not adversely affect the operability of the compositions for their intended use.