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:
Apr. 15, 1980
Filed:
Feb. 09, 1979
Hans-Georg Schmidt, Niederkassel, DE;
Dynamit Nobel Aktiengesellschaft, Troisdorf, DE;
Abstract
A method of preparing certain dihalogen vinyl cyclopropane carboxylic acid esters of the formula ##STR1## wherein R is an alkyl moiety and X is chlorine or bromine by exposing a dihalogen vinyl dihydrofuran of the formula ##STR2## to light, e.g., ultraviolet light. Also disclosed is a method for preparing such 2,4,4-trimethyl-3-carbalkoxy-5-(.beta.,.beta.-dihalogenvinyl)-4,5-dihydrof urans by reaction of a .beta.-alkoxycrotonic acid ester or 3,3-bisalkoxybutyric acid ester with a 1,1,1-trihalogen-4-methyl-3- or -4-pentene-2-ol in the presence of an acid catalyst. Also disclosed is a method of converting such 2,4,4-trimethyl-3-carbalkoxy-5-(.beta.,.beta.-dihalogenvinyl)-4,5-dihydrof uran by thermal rearrangement into 2,5,5-trimethyl-3-carbalkoxy-4-(.beta.,.beta.-dihalogenvinyl)-4,5-dihydrof urans. Such 2,4,4- and 2,5,5-trimethyl-3-carbalkoxy-5-(.beta.,.beta.-dihalogenvinyl)-4,5-dihydrof urans are new.