Hydrochloric Acid → 3-(Trifluoromethyl)-5,6,7,8-tetrahydro-[1,2,4]triazolo[4,3-a]pyrazine hydrochloride

Temperature

55 °C

A suspension of N′-((Z)-piperazin-2-ylidene)-trifluoroacetohydrazide (41 g) in methanol (170 mL) is stirred and heated to about 55° C. Hydrogen chloride (21 mL) is added to the reaction mixture and stirred for about 2 hours. The solution is cooled to 20° C. and methyl tert-butyl ether (423 mL) is added to it. The solution is further cooled to 0° C. and stirred for about 1 hour. The solid is filtered, washed with mixture of ethanol and methyl tert-butyl ether (82 mL) and dried at about 45° C. to afford the title compound. (Yield: 90.7%)

1. stirringstirred for about 2 hours
2. temperatureThe solution is cooled to 20° C.
3. temperatureThe solution is further cooled to 0° C.
4. stirringstirred for about 1 hour
5. filtrationThe solid is filtered
6. washwashed with mixture of ethanol and methyl tert-butyl ether (82 mL)
7. customdried at about 45° C.

ORD record

ord-3384ed1f2282478ca0e29f2343717547

Source dataset

uspto-grants-2012_11

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08309724B2