| 摘要 |
1,247,414. Preparing dimethylthiophosphite and organo phosphonous acid-O-monomethyl esters. FARBENFABRIKEN BAYER A.G. 19 May, 1969 [20 May, 1968], No. 25319/68. Heading C2C. Dimethylthiophosphite or an organothiophosphonous acid O-monomethyl ester are obtained by reacting trimethyl phosphite or an organophosphonous acid, O,O-dimethyl ester respectively with hydrogen sulphide and a weak organic base (the pKa of which in aqueous solution is from 0.5 to 8) at 0 to 70‹ C. and at a pressure of from 1 to 65 atmospheres absolute. Suitable organic bases include aniline, dimethyl- and diethyl-aniline, pyridine, picolines, collidines and trishydroxyisopropylamine. The organophosphonous acid O,O-dimethyl ester reactant may be methane-, ethane- or benzenephosphonous acid dimethyl ester. The products may be recovered by distillation of the reaction mixture or by extraction of the organic base and of the methanol formed with an aqueous solution of a strong inorganic acid. |
