2,4-Difluorobenzoic acid hydrazide → 7-{[2-Chloro-3-(trifluoromethyl)phenyl]carbonyl}-3-(2,4-difluorophenyl)-5,6,7,8-tetrahydro[1,2,4]triazolo[4,3-a]pyrazine

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Reaction Steps

A mixture of 1-{[2-chloro-3-(trifluoromethyl)phenyl]carbonyl}-5-(ethyloxy)-1,2,3,6-tetrahydropyrazine (0.167 g, 0.5 mmol, e.g. see preparation below) and 2,4-difluorobenzohydrazide (0.086 g, 0.500 mmol, CAS [118737-62-5], commercially available e.g. from Matrix Scientific or ABCR) in 1-butanol (1 ml) was heated at reflux for 1 hour. After cooling to room temperature the solvent was evaporated and the residue was purified by mass-directed automated (preparative) HPLC (MDAP). The residue was triturated with diethyl ether/isohexane and the solid was collected and dried to give 7-{[2-chloro-3-(trifluoromethyl)phenyl]carbonyl}-3-(2,4-difluorophenyl)-5,6,7,8-tetrahydro[1,2,4]triazolo[4,3-a]pyrazine (0.032 g) as a white solid. The solid was dried at 50° C. under high vacuum for 1 day.

Provenance & Evidence