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:
Nov. 21, 1995
Filed:
Dec. 16, 1993
Applicant:
Inventors:
Marc Halfon, Cranbury, NJ (US);
Craig A Polsz, Newtown, PA (US);
John H Hoare, Turnersville, NJ (US);
Assignee:
FMC Corporation, Philadelphia, PA (US);
Attorneys:
Primary Examiner:
Int. Cl.
CPC ...
C07D / ;
U.S. Cl.
CPC ...
5482632 ;
Abstract
This invention provides a process for optimizing the yield of a 1-(2,4-dichlorophenyl)-4,5-dihydro-1H-1,2,4-triazol-5-one by the chlorination in two steps of a 4,5-dihydro-1-phenyl-1H-1,2,4-triazol-5-one. The critical first step is the selective chlorination of the phenyl ring in the 4-position by addition of chlorine to a solution of the 4,5-dihydro-1-phenyl-1H-1,2,4-triazol-5-one in N,N-dimethylformamide. Chlorination of the product of the first step in acetic acid/water yields the 1-(2,4-dichlorophenyl)-4,5-dihydro-1H-1,2,4-triazol-5-one in high yield.