Synthesis of chiral amino cyclic phosphoric acids
Chiral amino cyclic phosphoric acids, 5-amino-2-hydroxy-4-(4-nitrophenyl)-1,3,2-dioxaphosphorinane 2-oxide and 2-hydroxy-4-(4-methylsulfonylphenyl)-5-phthalimido-1,3,2-dioxaphos phorinane 2-oxide are synthesized in good over yields (64.2% and 72.8% respectively) from 2-amino-1-aryl-1,3-propanediols. The different reaction conditions are necessary in hydrolysis reactions of amino cyclic phosphonyl chlorides.
Phenyl phosphorodichloridate in the synthesis of cyclic phosphate diesters of biological interest
The general usefulness of phenyl phosphorodichloridate (PPDC) in the synthesis of non-nucleoside cyclic phosphates is described. The method is illustrated with several examples including cyclic phosphates incorporating six to nine members. However, the reagent could not be used for the preparation of five-membered cyclic phosphates or 3′,5′-cycloadenylic acid (cAMP) from adenosine. Based on a number of observations, the conclusion was reached that PPDC cannot be used for the synthesis of strained or reactive cyclic phosphates. A convenient synthesis of cis- and trans-2-hydroxycyclopentanemethanol and a simple, quantitative method of separation of the two isomers is described. A number of cyclic phosphates were tested as substrates and inhibitors for cyclic purine phosphodiesterase and protein kinase.
Interaction of Diclofop-Methyl and MCPA on Wild Oats (Avena fatua)
Diclofop-methyl {methyl 2-[4-(2,4-dichlorophenoxy)phenoxy] propanoate} loses part of its activity on wild oats (Avena fatua L.) when it is applied in combination with ester or amine formulations of MCPA {[4-chloro-o-tolyl)oxy] acetic acid.} Uptake of diclofop-methyl is reduced in the presence of commercial formulations of MCPA, particularly amine formulations, which are only partly compatible with the diclofop-methyl formulation. With added MCPA, regardless of formulation, hydrolysis of diclofop-methyl to the acid diclofop is slowed down, both in intact wild oat plants and in a crude leaf extract. At the same time, conversion of any acid formed to inactive conjugates is accelerated in the presence of MCPA. It is concluded that the loss of activity of diclofop-methyl by MCPA can be accounted for by the effects of MCPA on uptake and metabolic conversion of diclofop-methyl.