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:
Aug. 01, 1995
Filed:
May. 27, 1994
Marc Halfon, Cranbury, NJ (US);
Eric W Sortore, Trenton, NJ (US);
FMC Corporation, Philadelphia, PA (US);
Abstract
An improved process for the difluoromethylation of a 1-phenyl-1H-1,2,4-triazol-5-one at the 4-position of the triazole ring with chlorodifluoromethane significantly reduces the amount of base required for the process, thereby reducing the environmental impact of the process by reducing the amount of by-product salts in the waste stream. The improvement comprises reacting the triazolinone with potassium carbonate in a solvent such as dimethylformamide, at a carbonate to triazolinone ratio in the range of about 0.55 to 1.0; reducing the water content of the reaction mixture to below about 2400 ppm by distillation; heating the reaction mixture in a sealed autoclave to 110.degree. to 180.degree. C., adding a 10 to 15 percent molar excess of chlorodifluoromethane, heating the reaction mixture at a temperature of 140.degree. to 210.degree. C. for 5 to 60 minutes, and recovering the difluoromethylated triazolinone.