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:
Jun. 01, 1982
Filed:
Feb. 27, 1981
Applicant:
Inventors:
David J Milner, Runcorn, GB;
David Holland, Runcorn, GB;
Assignee:
Imperial Chemical Industries Limited, London, GB;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
C07D / ; C07C / ;
U.S. Cl.
CPC ...
560124 ; 2524 / ; 549499 ;
Abstract
Process for the preparation of 3(2,2-dihalovinyl)-2,2-dimethyl cyclopropane carboxylic acids, especially permethrin acid ethyl ester, by reacting a diazoacetic acid ester with a 1,1-dihalo-4-methyl-1,3-pentadiene in the presence of a catalyst comprising a divalent rhodium salt of a carboxylic acid or borofluoric acid. The products have improved yields and better cis/trans isomer ratios than when the more common catalysts, e.g. copper-bronze, are used.