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:
Dec. 27, 1977
Filed:
Feb. 06, 1976
Alan Heymes, Portet sur Garonne, FR;
Jean-Pierre Maffrand, Toulouse, FR;
Parcor, Paris, FR;
Abstract
This invention relates to a process for the preparation of compounds having the formula: ##STR1## in which R.sub.1 is H or lower alkyl and R.sub.2 is H or lower alkyl, or phenyl or benzyl optionally substituted with at least one halogen or a lower alkyl, lower alkoxy, trifluoromethyl or nitro group. According to this method, a compound of the formula: ##STR2## in which R.sub.1 and R.sub.2 are as defined above and R.sub.3 is H or optionally substituted alkyl or benzyl, is reacted with a derivative Hal--SO.sub.2 --R (III) in which Hal is halogen and R is optionally substituted alkyl, aryl or aralkyl, to give a derivative of the formula: ##STR3## in which the various symbols have the above-defined meanings, and the sulfonated derivative of the formula (IV) is heated in the presence of an acid, to give the compound of the formula (I).