the present invention is directed to improved processes for manufacturing tex . tex is obtained by reacting suitable hexa - substituted piperazine derivatives with a strong acid and a nitrate source at temperatures greater than ambient temperature , and preferably in the range from about 50 ° c . to about 70 ° c . the reaction is exothermic and is complete within two to three hours . suitable hexa - substituted piperazine derivatives have the following general formula : ## str2 ## where -- or is a good leaving group and r is h , r &# 34 ;, -- cor &# 34 ;, -- coor &# 34 ;, -- so 3 r &# 34 ;, -- no , -- no 2 , acetal ( including aliphatic , cycloaliphatic , and branched acetals ), and cycloacetal ; r &# 39 ; is a nitrolysable group such as -- cor &# 34 ;, -- so 2 r &# 34 ;, -- no 2 , -- no , -- coor &# 34 ;, t - butyl , cyclohexyl , and isopropyl ; r &# 34 ; is h , c 1 to c 10 alkyl , branched alkyl , cyclo alkyl , and phenyl , substituted phenyl , and monocyclic heterocyclic compounds . as used herein , phenyl substituents include , but are not limited to , lower alkyl , branched alkyl , halogen , nitro , amino , substituted amino , alkoxy , acyl , and carbonyl containing moieties such as carboxyl , ester , ketone , etc . the monocyclic heterocyclic compounds used herein include heteroatoms selected from nitrogen , sulfur , and oxygen . the hexa - substituted piperazine derivatives used to prepare tex according to the present invention are preferably diacyltetraoxypiperazine derivatives . the following are examples of possible hexa - substituted piperazine derivatives which can be used in the process of the present invention : ## str3 ## typical hexa - substituted piperazine derivatives which may be used to synthesize tex are prepared by reacting glyoxal with an amide , sulfonamide , or sulfonate salt . other possible hexa - substituted piperazine derivatives which may be used in the present invention are reported in currie , a . c ., et al ., &# 34 ; base - catalysed reactions of glyoxal . part i . 1 , 4 - diformyl - and 1 , 4 - bismethylsulphonyl - derivatives of 2 , 3 , 5 , 6 - tetrahydroxypiperazines ,&# 34 ; journal of the chemical society ( sect . c ), pp . 491 - 496 ( 1967 ) and dinwoodie , a . h ., et al ., &# 34 ; base - catalysed reactions of glyoxal . part ii . 2 , 3 , 5 , 6 - tetrahydroxypiperazine - 1 , 4 - disulphonic acid derivatives ,&# 34 ; journal of the chemical society ( sect . c ), pp . 496 - 497 ( 1967 ). as used herein , diacyltetraoxypiperazine derivatives also include tex intermediate products , such as the tetraoxadiazaisowurtzitane derivatives shown below , because the tetraoxadiazaisowurtzitane derivatives may be prepared from diacyltetraoxypiperazine derivatives . tex is prepared from the tetraoxadiazaisowurtzitane derivatives by nitrolysis of the n - acyl group . ## str4 ## while not being bound by theory , it is believed the strong acid serves to catalyze the isowurtzitane structure formation . it is also believed the strong acid helps create nitronium ions from the nitrate source necessary to nitrate the tex . typical strong acids which may be used in the process of the present invention include sulfuric acid , trifluoroacetic acid ( tfa ), trifluoroacetic anhydride ( tfaa ), and hcl . nitrate sources which have been used successfully in the present invention include nitric acid and ammonium nitrate . importantly , commercially available 70 % or 90 % nitric acid may be used in the present invention instead of 100 % nitric acid required in the literature preparation . the currently preferred strong acid and nitrate source is an acid mixture of nitric acid and sulfuric acid . this acid mixture may contain up to 60 % concentrated h 2 so 4 , by volume . the presently preferred ratio of concentrated nitric acid ( 90 %, 1 . 52 gm / ml ) to concentrated sulfuric acid is 60 : 40 , by volume . it has been found that nitric acid ( 90 % and 100 % nitric acid ) can serve as both the strong acid and nitrate source in the process of preparing tex according to the present invention . the amount of acid mixture required to prepare tex ranges from about 2 : 1 to about 5 : 1 milliliters acid mixture per gram substrate , and preferably is about 4 : 1 . when ammonium nitrate is the nitrate source , from two to ten equivalents of ammonium nitrate are used for each equivalent of substrate . the reaction product is precipitated , preferably by pouring onto ice , filtered , and purified to yield tex . currently preferred purification techniques include heating the reaction product in nitric acid , washing with methanol , and / or washing with a base to neutralize excess acid . the pure product may be obtained by crystallization according to standard crystallization techniques . typical crystallization solvents which may be used include acetonitrile , acetone , butyrolactone , nitric acid , ethyl acetate , pyridine , dmso , and dmf . during the synthesis of tex , nitric acid is reduced and produces no 2 . other nitrate sources , such as ammonium nitrate , also produce no 2 during nitrolysis . if the reaction temperature becomes too high , no 2 is rapidly released , causing the reaction mixture to undergo an uncontrolled exotherm . it has been found that urea added to the reaction mixture scavenges no 2 , inhibits foaming , and diminishes the likelihood of uncontrolled exotherm . thus , urea is a preferred additive to the tex reaction mixture . typically , at least 0 . 5 equivalents urea ( based upon the amount of diacyltetraoxypiperazine derivatives ) is needed to be effective . it is currently preferred to include about 1 equivalent of urea in the reaction mixture . those skilled in the art will appreciate that a significant excess amount of urea can be used , it is not preferred because it can lead to byproduct formation and can complicate purification . as described more fully in the related application ser . no . 08 / 013 , 034 , filed feb . 3 , 1993 , titled &# 34 ; insensitive high performance explosive compositions ,&# 34 ; tex may be used either alone or in combination with conventional or novel solid explosive ingredients as the basis for formulating very high performance insensitive explosive compositions . for example , tex may be used in combination with a binder , metal , and oxidizer to prepare low cost , castable explosives . tex and a small amount of binder may also be used to prepare high solids (& gt ; 90 % tex ) pressable or extrudable explosives . melt cast explosives may be prepared by combining tex with an energetic or inert material having a relatively low melt temperature (& lt ; 120 ° c .). these melt cast explosives may also contain a metal , oxidizer and other nitramine . tex may also be used as the primary solid in simple castable or plastic formulations ( up to 90 % solids ) using energetic or inert polymeric binders . this class of explosives may contain another nitramine ( i . e ., rdx , hmx ), but will not normally contain an oxidizer or metal . the following examples are offered to further illustrate the synthesis methods of the present invention . these examples are intended to be purely exemplary and should not be viewed as a limitation on any claimed embodiment . a mixture of 4 . 0 g ( 20 mmol ) 2 , 3 , 5 , 6 - tetrahydroxy - 1 , 4 - diformylpiperazine ( thdfp ) and glyoxal trimer , 2 . 1 g ( 10 mmol ) was added to a stirred solution of concentrated sulfuric acid , 25 ml , while maintaining the temperature at 0 ° c . with an ice water bath . following the addition the bath was removed and the temperature was allowed to rise to 15 ° c . after five hours at this temperature the reaction mixture was again cooled to 0 ° c . by reapplication of the ice water bath . freshly distilled 100 % hno 3 , 25 ml ( prepared from 90 % hno 3 and h 2 so 4 ) was added dropwise . stirring was continued for 2 hours at 0 ° c . then 48 hours at room temperature . the mixture was then poured on ice and the solid precipitate collected by filtration , washed with water and then ethanol several times . after drying under vacuum at 60 ° c . the weight of the solid was 3 . 3 g . subsequent analysis of this material by 1 h nmr indicated that the product was predominantly unchanged glyoxal trimer containing only a small amount of tex (& lt ; 20 %). repeated digestions and recrystallizations from ethyl acetate and acetonitrile provided an analytical sample which displayed the proton and carbon nmr resonances as well as ftir absorbances reported by joseph h . boyer and colleagues in heterocycles , vol . 31 , pp . 479 - 80 ( 1990 ). to a water cooled , vigorously stirred solution of 390 ml of white fuming nitric acid and 250 ml of concentrated sulfuric acid in a 4 liter erlenmeyer flask was added a mixture of 206 g ( 1 . 0 mole ) of thdfp and 33 g ( 0 . 55 mole ) urea , portionwise such that the temperature did not exceed 50 ° c . following the addition the water bath was removed and the temperature was allowed to rise to 65 ° c . the temperature gradually fell to approximately 30 ° c . over one half hour , following which the entire contents of the flask were poured on ice and the solid precipitate collected on a glass frit . the solid was then washed thoroughly with water , saturated sodium bicarbonate , water again , and finally methanol . the crude product was then dried in vacuo at 60 ° c . overnight , furnishing 108 . 8 g of a pale yellow solid which when analyzed by 1 h nmr indicated a purity of 97 % ( 3 % mono - formyl - mononitro ). an analytical sample was prepared by several recrystallizations from acetonitrile which was indistinguishable from that described by boyer et al . 1 h nmr ( varian 300 mhz )( dmso d6 ); δ7 . 08 ( s , 4h ), δ5 . 95 ( s , 2h ); 13 c nmr ( dmso d6 ); δ102 . 65 , δ82 . 63 ir : 1590 , 1285 , 1250 , 1050 , 900 , 875 cm - 1 anal . calculated for c 27 . 4 %, h 2 . 29 %, n 21 . 3 %; found : c 27 . 4 %, h 2 . 24 %, n 20 . 9 %. tex was prepared based upon the procedure of example 2 , except that the procedure was carried out under a variety of different conditions and range of acids to produce tex . table 1 illustrates the breadth of parameters . table 1______________________________________ thdfp acid acid urea yieldexample ( gm ) ( ml ) ratio * ( gm ) ( gm ) ______________________________________ 3 50 101 . 1 61 / 40 0 37 . 1 4 200 500 3 / 2 33 65 5 100 850 1 . 5 / 7 33 16 . 2 6 200 500 3 / 2 66 48 . 6 7 206 500 3 / 2 100 36 . 0 8 206 650 2 . 5 / 4 33 63 . 0 9 206 640 2 . 5 / 3 . 9 66 70 . 010 200 500 3 / 2 0 48 . 411 100 500 1 / 1 0 31 . 412 100 400 2 . 5 / 1 . 5 0 20 . 013 100 300 1 . 8 / 1 . 2 0 9 . 314 100 400 3 / 1 0 24 . 0______________________________________ *( v / v ) 90 % hno . sub . 3 / concentrated h . sub . 2 so . sub . 4 a suspension of 50 . 0 g of crude ( any material with a purity of less than 99 % by nmr ) tex in 200 ml of white fuming nitric acid was prepared in a 500 ml round bottom flask . the flask was fitted with a condenser and the contents heated to 80 ° c . with an oil bath for 8 hr . the yellow solution was then allowed to cool to room temperature and subsequently poured on ice . the solid was collected , washed with water , sodium bicarbonate and more water . the product was then dried in vacuo yielding 31 . 42 g of analytically pure (& gt ; 99 %) tex . to a solution of 24 ml of white fuming nitric acid and 16 ml of concentrated sulfuric acid was added 1 , 4 - bismethylsulfonyl - 2 , 3 , 4 , 5 - tetrahydroxypiperazine ( prepared according to currie , a . c . et al ., journal of the chemical society ( sect . c )., pp . 491 - 496 , ( 1967 )), 15 . 0 g ( 0 . 048 mole ). after one half hour the reaction began to fume and the temperature rose to above 100 ° c . at this point the mixture was poured on ice and the solid collected . this material was then washed with water and air dried . the solid was then extracted with hot ethyl acetate leaving 5 . 5 g of unreacted starting material . the filtrate was evaporated in vacuo resulting in a pale yellow solid 600 mg composed predominately of tex by 1 h nmr . in a 100 ml 3 neck round bottom flask equipped with a stir bar thermometer , argon inlet and outlet was placed 50 ml of trifluoroacetic anhydride . the flask was immersed in an ice bath and 9 ml ( 0 . 194 mole , 12 . 3 g ) of freshly distilled 100 % nitric acid added dropwise with stirring . after one half hour at 0 ° c . 10 g ( 48 . 5 mmole ) of dfthp was added in one portion . the reaction was allowed to stir overnight at room temperature after which 3 ml of water was added . the solid was then collected by filtration and subsequently washed with methanol twice , then ether twice . after air drying the white solid weighed 16 . 5 g . this material was recrystallized from acetone yielding pure dfiw melting sharply at 169 ° c . 1 h nmr bs ( cho ) δ8 . 75 ( 2h ), bs + shoulder δ7 . 10 , 7 . 22 ( 6h ); 13 c nmr δ168 . 75 ( cho ), δ85 . 12 ( ch ), δ78 . 89 ( ch ); ir ; 1650 , 1220 , 935 , 790 cm - 1 . in a 50 ml round bottom flask equipped with a stir bar and argon inlet was placed 3 ml of white fuming nitric acid and 1 . 0 g ( 4 . 4 mmole ) of dfiw prepared according to example 17 . the solution thus prepared was stirred overnight at room temperature . the reaction was then poured on ice and the solid precipitate collected , washed with water and dried in vacuo , yielding 0 . 23 g of tex . in a 50 ml round bottom flask equipped with a stir bar and argon inlet was placed 25 ml of white fuming nitric acid and 20 drops of concentrated hydrochloric acid . to this solution was added tadfp ( prepared according to currie , a . c . et al ., journal of the chemical society ( sect . c ), pp . 491 - 496 , ( 1967 )) in one portion . the reaction gradually became clear and stirring was continued overnight at room temperature . after this time the reaction was poured on ice and the solid precipitate collected by filtration , washed thoroughly with water and dried yielding 500 mg of tex as a pale yellow solid . in a dry 100 ml , single neck round bottom flask equipped with a stir bar and argon inlet was placed 1 . 0 g of solid so 3 ( 12 . 5 mmole ). the flask was then immersed in an ice bath and freshly distilled 100 % nitric acid , 4 . 0 ml ( 96 . 5 mmole ) was added dropwise via syringe . the suspension was stirred for one half hour by which time all the so 3 had dissolved resulting in a pale yellow solution . the sulfonate salt 1 . 0 g ( 3 . 2 mmole ) was then added in portions over 2 - 3 minutes . the cooling bath was then removed and stirring continued overnight . the reaction was then poured on ice and the solid collected by filtration . after drying the product was analyzed by 1 h nmr and found to contain tex heavily contaminated with reaction byproducts . in a one liter erlenmeyer flask containing a magnetic stir bar was placed 180 ml of 70 % nitric acid . the flask was cooled in an ice bath and thdfp , 103 g ( 0 . 5 mole ) was added in several portions . no temperature rise was observed during or following the addition and the suspension thus prepared was stirred overnight at room temperature . the mixture was then poured on ice and the solid collected by filtration . after air drying the solid was dissolved in a 2 : 1 mixture of ethyl acetate and methanol , and passed through a short pad of silica gel on a filter frit . the filtrate was allowed to stand for two days at which time the crystals which had deposited were collected and dried in vacuo , providing 8 . 3 g of pure tex . nitric acid of higher concentration may be substituted in this reaction but the yields under similar conditions are not substantially higher ; e . g . : with 100 % hno 3 , 1 . 0 g thdfp gave 200 mg of tex and with 90 % hno 3 , 50 g thdfp gave 12 . 0 g tex . in a one liter erlenmeyer flask with a large stir bar was placed 750 ml of concentrated sulfuric acid . to the acid was added 240 g of oven dried ammonium nitrate in portions while maintaining the temperature below 50 ° c . to the resulting clear solution was added dfthp , 206 g ( 1 mole ) in two large portions . the thick reaction mixture was stirred at room temperature overnight . another 160 g of ammonium nitrate was then added and the exothermic process was allowed to subside ( about 4 hours ) after which time the slurry was poured on ice and the solid collected by filtration . the solid was then washed with sodium bicarbonate , then water and air dried . the dried solid was then extracted with boiling ethyl acetate and after cooling two crops of impure tex was collected totalling 46 g . one additional crystallization from ethyl acetate gave 20 g of clean tex . preparation of tex via 4 , 10 - diacetyl - 2 , 6 , 8 , 12 - tetraoxa - 4 , 10 - diazatetracyclo [ 5 . 0 . 0 5 , 9 0 3 , 11 ] dodecane ( daiw ) in a 500 ml round bottom flask equipped with a stir bar and thermometer was placed 100 ml of 40 % glyoxal solution ( 0 . 69 mole ) to which was added 46 . 6 ml ( 1 . 38 mole ) of concentrated ammonium hydroxide solution . during the addition the temperature rose to 70 ° c . the resulting brown solution was stirred with cooling in an ice bath for two hours after which the water was removed in vacuo . five grams of this amorphous brown tar was then treated with acetyl nitrate in acetic anhydride ( prepared from 25 ml acetic anhydride and 4 ml 100 % hno 3 at 0 ° c .). following an aqueous work up the product , daiw , 2 . 60 g , was obtained as a pale yellow oil which slowly crystallized . one half gram of this material was then treated with 2 ml of 100 % hno 3 at 40 ° c . for 2 hours . the mixture was then poured on ice and the solid precipitate collected by filtration . after thoroughly washing with water , the solid was dried in vacuo providing 80 mg of tex as a pale yellow solid . in a 250 ml round bottom flask equipped with a stir bar , thermometer , and argon inlet was placed a mixture of 20 ml 25 % oleum and 54 . 5 ml white fuming nitric acid . a mixture of dfthp , 51 . 5 g ( 250 mmole ) and urea , 15 g ( 250 mmole ) was then added portionwise over 20 minutes . the temperature during this addition was 52 ° c ., following the addition the temperature increased to 65 ° c . over 11 minutes . after another one half hour the temperature had dropped to 28 ° c ., at which time the whole contents were poured on ice . the solid was then collected by filtration , washed sequentially with water , saturated sodium bicarbonate , more water and finally air dried . tex was obtained as pale yellow solid , 10 . 5 g . from the foregoing it will be appreciated that the present invention provides alternative processes for manufacturing tex which are efficient , produce tex in high yield , and are rapid . the present invention also provides processes for manufacturing tex which utilize readily available reactants . the invention may be embodied in other specific forms without departing from its spirit or essential characteristics . the described embodiments are to be considered in all respects only as illustrative and not restrictive . the scope of the invention is , therefore , indicated by the appended claims rather than by the foregoing description . all changes which come within the meaning and range of equivalency of the claims are to be embraced within their scope .