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. 09, 1985
Filed:
Jan. 31, 1983
Applicant:
Inventors:
Karl H Agback, Upsala, SE;
Alf S Nygren, Orbyhus, SE;
Assignee:
Pharmacia AB, Upsala, SE;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
C07C / ; C09B / ; C09B / ; C09B / ;
U.S. Cl.
CPC ...
534599 ; 2604 / ; 2604 / ; 534583 ; 534588 ; 534660 ; 534730 ; 534887 ;
Abstract
A method of preparing 3,3'-azo-bis-(6-hydroxy benzoic acid) of formula I ##STR1## and salts thereof in at least 98% purity for treating inflammatory intestinal diseases. According to the invention a compound II ##STR2## is diazotized, and the diazonium salt obtained is coupled with a compound III ##STR3## The formed intermediate IV, which is also comprised by the invention, ##STR4## is hydrolized in alkaline medium to form the compound I. R.sub.1, R.sub.2 and R.sub.3 signify lower alkyl, R.sub.2 also possibly substituted phenyl.