The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jul. 12, 1977
Filed:
Nov. 03, 1975
Ciba-Geigy Corporation, Ardsley, NY (US);
Abstract
1,3,4-Thiadiazol-5-(4H)-onyl-(4)-methyl dithiophosphoric acid ester of the formula ##STR1## wherein each of R, R.sub.1 and R.sub.2 methyl or ethyl and Y represents oxygen or sulphur, are prepared by condensing a thiophosphate acid of the formula ##STR2## or an alkali metal or ammonium salt thereof, with a 1,3,4-thiadiazole of the formula ##STR3## with formaldehyde in an aqueous medium consisting essentially of 60-98 wt % of sulphuric acid, the amount of sulphuric acid is at least 0.7 mol per mol of free thiophosphoric acid, if free acid is used, and 1.7 mol per mol of thiophosphoric acid salt, if a salt is used. The temperature of the reaction mixture is maintained at 15.degree.-60.degree. C. The process is particularly useful in the preparation of O,O-dimethyl-S-[2-methoxy-1,3,4-thiadiazol-5(4H)-onyl-(4)-methyl]-dithioph osphate (methidathion).
Data source: USPTO (United States Patent and Trademark Office) public patent records. Weekly synchronization. How IDiyas builds this profile