Phosgene → 2-Isocyanato-5-(trifluoromethyl)-1,3,4-thiadiazole

A saturated solution of phosgene in ethyl acetate (100 ml) was charged into a glass reaction vessel equipped with a mechanical stirrer. A slurry of 2-trifluoromethyl-5-amino-1,3,4-thiadiazole (45 grams) in ethyl acetate (300 ml) was added to the reaction vessel and the resulting mixture was stirred for a period of about 16 hours resulting in the formation of a precipitate. The reaction mixture was then purged with nitrogen gas to remove unreacted phosgene. The purged mixture was filtered to recover 48 grams of a white solid. This solid was recrystallized from dimethyl formamide to yield the desired product 2-trifluoromethyl-1,3,4-thiadiazol-5-yl isocyanate dimer.

1. customequipped with a mechanical stirrer
2. customresulting in the formation of a precipitate
3. customThe reaction mixture was then purged with nitrogen gas
4. customto remove unreacted phosgene
5. filtrationThe purged mixture was filtered
6. customto recover 48 grams of a white solid
7. customThis solid was recrystallized from dimethyl formamide

ORD record

ord-f63ad0f9e8b54a57a755720fca48d86c

Source dataset

uspto-grants-1976_04

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US03951640