Trifluoroacetic acid → HCID 69479932, compound

Participants

Reaction Steps

(S)-2-{[1-(Tert-butoxycarbonyl)piperidin-4-yl]-N-methylaminomethyl}-2-methyl-6-nitro-2,3-dihydroimidazo[2,1-b]oxazole prepared in Example 225 (400 mg, 1.01 mmol) was dissolved in methylene chloride (1 ml). To the solution, trifluoroacetic acid (1 ml) was added followed by stirring at room temperature for 5 hours. The reaction mixture was concentrated under reduced pressure and added methylene (1 ml) chloride and triethylamine (2 ml). The solution was stirred at room temperature for 5 minutes and then concentrated under reduced pressure, and the residue was dissolved in DMF (8 ml). To the solution, a mixture of 4-(trifluoromethyl)benzyl alcohol (267 mg, 1.51 mmol) and 1,1′-carbonyldiimidazole (246 mg, 1.51 mmol) in DMF (2 ml) stirred at room temperature for 4 hours was added followed by stirring at room temperature overnight. The reaction mixture was poured into water and extracted with ethyl acetate. The organic phase was washed with a saturated saline solution, dried over magnesium sulfate and then filtered. The resulting filtrate was concentrated under reduced pressure. The residue was purified by silica gel column chromatography (methylene chloride/methanol=200/1) and crystallized from methylene chloride-isopropyl ether to afford (S)-2-{[l-(4-trifluoromethylbenzyloxycarbonyl)piperidin-4-yl]-N-methylaminomethyl}-2-methyl-6-nitro-2,3-dihydroimidazo[2,1-b]oxazole (341 mg, yield 68%) as a light yellow powder.

Provenance & Evidence