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

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Reaction Conditions

Reaction Steps

3-(4-Pyridinyl)-5,6,7,8-tetrahydro[1,2,4]triazolo[4,3-a]pyrazine (0.150 g, 0.745 mmol, e.g. prepared as described below) was treated with N,N-dimethylformamide (DMF) (3 mL) and cooled to 0° C. Triethylamine (0.109 mL, 0.783 mmol) and N,N-dimethyl-4-pyridinamine (DMAP) (0.009 g, 0.075 mmol) were added at 0° C. under argon and the mixture was stirred for 5 minutes; then 2-chloro-3-(trifluoromethyl)benzoyl chloride (0.199 g, 0.820 mmol, commercially available e.g. from Apollo Scientific or Shanghai FWD Chemicals) was added. The reaction mixture was kept at 0° C. for ½ hour. The reaction was quenched with water, extracted with ethyl acetate (two extractions), and the combined organic phases were washed with a saturated sodium bicarbonate solution, followed by water (four washes). The organic phase was dried, and evaporated to give a yellow oil. The residue was purified by silica gel chromatography using 0-20% of methanol in Dichloromethane as the eluent and then triturated with diethyl ether to give 7-{[2-chloro-3-(trifluoromethyl)phenyl]carbonyl}-3-(4-pyridinyl)-5,6,7,8-tetrahydro[1,2,4]triazolo[4,3-a]pyrazine as a white solid. The solid was dried at 50° C. on the high vacuum for 1 day.

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