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. 08, 1986
Filed:
May. 29, 1984
Stephen Lachhein, Morfelden-Walldorf, DE;
Hilmar Mildenberger, Kelkheim, DE;
Hoechst Aktiengesellschaft, Frankfurt am Main, DE;
Abstract
The invention relates to a new process for the preparation of compounds of the formula (I) ##STR1## in which R.sub.1 denotes alkyl and R.sub.2 denotes H, acetyl or propionyl, by addition of compounds of the formula II ##STR2## onto compounds of the formula III, using radical-formers, the radical-formers being used being compounds of the general formula IV ##STR3## in which R.sub.3 denotes alkyl or phenyl and R.sub.4 denotes alkyl, the reaction being carried out at temperatures in the range from 50.degree. to 100.degree. C., and, for the preparation of compounds of the formula I where R.sub.2 is H, then splitting off the radical R.sub.2.sup.'. Using this process, the compounds of the formula I are obtained in high yield and particular purity.