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:
Aug. 26, 1980
Filed:
Apr. 13, 1979
Hans-Jochem Riebel, Selters, DE;
Claus Stolzer, Wuppertal, DE;
Bayer Aktiengesellschaft, Leverkusen, DE;
Abstract
In the preparation of O,O-diethyl-O-(1-phenyl-2-cyano-prop-1-enyl)-thionophosphoric acid ester by reacting a benzoic acid ester with propionitrile in the presence of an alkali metal alcoholate and then reacting the reaction mixture with O,O-diethyl-thionophosphoric acid diester chloride, the improvement which comprises employing about 5 to 50 moles of the propionitrile per mole of benzoic acid ester, distilling off the alcohol obtained during the reaction of propionitrile, benzoic acid ester and alcoholate before the addition of the O,O-diethyl-thionophosphoric acid diester chloride, and maintaining the volume of the reaction mixture approximately constant by adding propionitrile during the distillation. Advantageously the alcoholate is sodium methylate, ethylate or tert.-butylate or potassium methylate, ethylate or tert.-butylate, the reaction is effected at about 80.degree. to 120.degree. C., about 5 to 25 moles of propionitrile are employed per mole of benzoic acid ester, about 1 to 1.3 moles of benzoic acid ester and about 1 to 1.15 moles of alkali metal alcoholate are employed per mole of O,O-diethyl-thionophosphoric acid diester chloride, and the benzoic acid ester is the methyl ester or ethyl ester.