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. 06, 1994
Filed:
Nov. 30, 1992
Applicant:
Inventor:
Clarke Slemon, Willowdale, CA;
Assignee:
Torcan Chemical Ltd., Aurora, CA;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
C07D / ; C07D / ; C07D / ; C07D / ;
U.S. Cl.
CPC ...
549 73 ; 549 70 ; 549 71 ; 549 80 ;
Abstract
3-substituted thiophene compounds contaminating the analogous 2-substituted thiophene compounds, e.g. 3-acetylthiophene contaminating 2-acetyl thiophene, are removed by a selective electrophilic substitution process, e.g. bromination, followed by fractional distillation. It has been found that electrophilic substitution as exemplified by bromination is highly selective towards the 3-substituted thiophenes, yielding compounds of significantly higher molecular weights for separation purposes, to give high purity 2-substituted thiophene compounds.