摘要:
The methyl ester of O,O-dimethyl-dithiophosphoryl acetic acid is prepared with minimal formation of by-products by reacting the sodium salt of O,O-dimethyl-dithiophosphoryl acid with the methyl ester of 2-chloroacetic acid at a pH of 5.5 to 7, at relatively high temperatures, of the order of 80.degree. to 100.degree. C, for reaction times of 10 to 15 minutes. The process can be carried out continuously.
摘要:
Process for the production of alkyl trifluoroacetates by esterification of trifluoroacetyl chloride with alkyl alcohols, wherein the trifluoroacetyl chloride/alcohol molecular ratio is greater than 1; alkyl trifluoroacetate is recovered by condensation at temperatures lower than -30.degree. C.
摘要:
The N-monomethylamide of O,O-dimethyl-dithiophosphorylacetic acid is prepared continuously, in the form of essentially pure, beautiful colorless crystals, by reacting the methyl ester of O,O-dimethyldithiophosphoryl acetic acid with a 34% aqueous solution of methylamine (CH.sub.3 NH.sub.2) at a temperature between 0.degree. C and 10.degree. C, in water containing a surfactant which is an alkyl sulphonate or an alkylarylsulphonate and, as an essential feature of the process, recycling, back to the reaction vessel, from 1/10 to 1/20 of the slurry obtained as a result of the reaction between the methyl ester of O,O-dimethyl-dithiophosphorylacetic acid and the 34% solution of CH.sub.3 NH.sub.2.