Triethylamine → (S)-[4-(2-methyl-6-nitro-2,3-dihydroimidazo[2,1-b]oxazol-2-ylmethyl)piperazin-1-yl]-(4-trifluoromethylphenyl)methanone

Participants

Reaction Steps

(S)-2-Methyl-6-nitro-2-(piperazin-1-ylmethyl)-2,3-dihydroimidazo[2,1-b]oxazole dihydrochloride prepared in Example 408 (2.36 mg, 0.882 mmol) was suspended in methylene chloride (10 ml). To the suspension, triethylamine (1 ml, 7.17 mmol) was added. To the solution, 4-(trifluoromethyl)benzoyl chloride (193 mg, 0.926 mmol) was added with cooling on ice-bath followed by stirring at room temperature for 1 hour. The reaction mixture was washed with a saturated sodium hydrogencarbonate solution, water and a saturated saline solution in this order, dried over sodium sulfate and then filtered. The filtrate was concentrated under reduced pressure, and the residue was purified by silica gel column chromatography (methylene chloride/methanol=50/1) to afford (S)-[4-(2-methyl-6-nitro-2,3-dihydroimidazo[2,1-b]oxazol-2-ylmethyl)piperazin-1-yl]-(4-trifluoromethylphenyl)methanone (264 mg, yield 68%) as a white powder.

Provenance & Evidence