Process for the preparation of thiophosphoric acid esters

US4416834A · kind A · utility

Assignee

• BAYER HEALTHCARE LLC · DE

Inventors

• Peter Feyen · Mettmann, DE
• Friedrich Schmidt · Wuppertal, DE

Key dates

• Filing date: Sep 24, 1980
• Grant date: Nov 22, 1983
• Expiry date: Sep 24, 2000

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C07F9/1651
• WIPO field: Organic fine chemistry
• WIPO sector: Chemistry

Abstract

A process for the preparation of a compound of the formula ##STR1## in which R is alkyl, PA1 X is oxygen or sulphur and PA1 R' is hydrogen or alkyl, comprising reacting a thiophosphate of the formula ##STR2## in which M is a cation other than NH.sub.4.sup..sym., with an ethylmercapto compound of the formula ##STR3## in which Y is a fugitive group, in a polar reaction medium at a temperature between about 30.degree. and 80.degree. C. and at a pH between about 2 and 9. Advantageously X is oxygen and the thiophosphate is produced by reaction of a dialkyl phosphite of the formula ##STR4## with sulphur in the presence of an organic base in an organic solvent and subsequent extraction with aqueous MOH solution. Also Y is advantageously chlorine and the ethylmercapto compound is prepared by heating the corresponding alcohol to about 40.degree.-100.degree. C. and passing hydrogen chloride gas into the pre-warmed alcohol, the reaction solution being used directly without working up.