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:
Sep. 22, 1998
Filed:
Nov. 20, 1996
Kureha Chemical Industry Co., Ltd., Tokyo, JP;
Abstract
This invention relates to methods for substitution of an amino group of a heterocyclic primary amine by a chlorine atom and synthesis of 2-chloro-5-methylthiazole and its derivatives by application thereof. Typically, a heterocyclic primary amine and sodium nitrite are caused to react in the presence of hydrochloric acid, followed by heating the formed diazonium base at 30.degree.-100.degree. C. in the presence of an equimolar or more of hydrochloric acid to substitute the amino group by the chlorine atom. Further, 2-amino-5-methylthiazole and sodium nitrite are caused to react in the presence of hydrochloric acid, followed by heating the formed diazonium base at 30.degree.-100.degree. C. in the presence of an equimolar or over of hydrochloric acid to give 2-chloro-5-methylthiazole. Then, the resultant 2-chloro-5-methylthiazole is caused to react with a chlorinating agent to give 2-chloro-5-chloro-methylthiazole.