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:
Oct. 01, 1991
Filed:
Apr. 18, 1990
Applicant:
Inventor:
Wilhelm Kump, Biel-Benken, CH;
Assignee:
Ciba-Geigy Corporation, Ardsley, NY (US);
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
C07D / ;
U.S. Cl.
CPC ...
544368 ; 540468 ;
Abstract
The invention relates to a process for the preparation of a compound of formula ##STR1## or a salt thereof, wherein R.sub.1 is hydrogen or trialkylacetyl, R.sub.2 is hydrogen or acetyl and R.sub.3 is alkyl, which process comprises cyclising a compound of formula ##STR2## wherein R.sub.1 is trialkylacetyl and, if desired, converting a compound of formula I obtainable by said process or in another manner, or a salt thereof, into another compound of formula I or a salt thereof, or converting a resultant free compound of formula I into a salt and/or a resultant salt into the free compound of formula I or into another salt.