18882-44-5Relevant articles and documents
Preparation of dithiophosphoric acid diester-halides
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, (2008/06/13)
A process for the preparation of a dithiophosphoric acid diester-halide of the formula STR1 IN WHICH R1 is alkyl with 1 to 10 carbon atoms, aralkyl with 1 to 6 carbon atoms in the alkyl radical, or alkoxyalkyl or alkylthioalkyl with 1 to 5 carbon atoms in each alkyl radical, R2 is alkyl with 1 to 8 carbon atoms, and Hal is halogen, Which comprises reacting an S-alkyl or S-aralkyl ester of a dithiophosphoric acid dihalide of the formula STR2 WITH ABOUT A 5 TO 300% MOLAR EXCESS OF AN ALCOHOL OF THE FORMULA in the presence of about a 5 to 300% molar excess of a tertiary pyridine base or tertiary aralkyl-alkylamine at a temperature between about -10° and +60° C. Advantageously the tertiary base is pyridine, 2-, 3- or 4-methyl-pyridine, 4-ethyl-pyridine, 5-ethyl-2-methyl-pyridine, 2,4- or 2,6-dimethyl-pyridine, 2,4,6-trimethyl-pyridine, quinoline, isoquinoline, 2-, 4- or 6-methyl-quinoline, 6-chloro-2-methyl-quinoline, 2-chloro-4-methyl-quinoline, 8-chloro-2-methyl-quinoline or dimethylbenzylamine, the reaction is carried out at about 0° to 30° C., the alcohol is ethanol employed in about a 15 to 30% molar excess, about a 20 to 210% molar excess of the tertiary base is employed, R1 is alkyl with 1 to 8 carbon atoms, aralkyl with 1 to 3 carbon atoms in the alkyl radical, or alkoxyalkyl or alkylthioalkyl with 1 to 3 carbon atoms in each alkyl radical and Hal is chlorine.
