4-Fluorobenzamide → HCID 14087130, compound

Participants

Reaction Steps

In still a further embodiment, 1-(3-(4-fluorophenyl)-1,2,4-thiadiazol-5-yl)ethanone may be prepared according to the methodology and reagents of Scheme 16A. In this embodiment, a 1,3,4-oxathiazol-2-one ring fragment is generated and subsequently converted to a 1,2,4-thiadiazole ring fragment during the preparation of 1-(3-(4-fluorophenyl)-1,2,4-thiadiazol-5-yl)ethanone. Specifically, 4-fluoro-benzamide is reacted with chlorocarbonylsulfenyl chloride to provide 5-(4-fluoro-phenyl)-1,3,4-oxathiazol-2-one. In one embodiment, the reaction is performed in toluene. In another embodiment, the reaction is performed at elevated temperatures of about 80° C. for about 3 hours. 5-(4-Fluorophenyl)-1,3,4-oxathiazol-2-one is then reacted with acetyl cyanide to provide 1-(3-(4-fluorophenyl)-1,2,4-thiadiazol-5-yl)-ethanone. In one embodiment, this reaction is performed in 1,2-dichlorobenzene. In another embodiment, this reaction is performed at elevated temperatures of about 160° C. for about 20 hours. 1-(3-(4-Fluorophenyl)-1,2,4-thiadiazol-5-yl)ethanone is then converted to a compound of Formula (I-A) by the methods described herein, such as Scheme 1.

Provenance & Evidence