Trifluoroacetic acid → HCID 86760533, compound

Participants

Reaction Steps

Tert-butyl (S)-[1-(2-methyl-6-nitro-2,3-dihydroimidazo[2,1-b]oxazol-2-ylmethyl)piperidin-4-yl]carbamate prepared in Example 283 (0.300 g, 0.787 mmol) was dissolved in methylene chloride (4 ml). To the solution, trifluoroacetic acid (2 ml) was added followed by stirring at room temperature for 2 hours. The reaction mixture was concentrated under reduced pressure, and added methylene chloride (4 ml) and triethylamine (4 ml). The mixture was stirred at room temperature for 5 minutes and concentrated under reduced pressure. The residue was dissolved in DMF (6 ml). To the solution, a mixture of 4-(trifluoromethyl)benzyl alcohol (0.166 g, 0.944 mmol) in DMF (4 ml) and 1,1′-carbonyldiimidazole (0.153 g, 0.944 mmol) stirred at room temperature for 4 hours was added followed by stirring at room temperature overnight and then at 65° C. for 8 hours. To the reaction mixture, water was added, and the solution was extracted with ethyl acetate twice. The organic phases were combined, washed with water and a saturated saline solution, dried over sodium sulfate and then filtered. The resulting filtrate was concentrated under reduced pressure. The residue was purified by silica gel column chromatography (n-hexane/acetone=2/1) and recrystallized from ethyl acetate to afford 4-trifluoromethylbenzyl (S)-[1-(2-methyl-6-nitro-2,3-dihydroimidazo[2,1-b]oxazol-2-ylmethyl)piperidin-4-yl]carbamate (0.107 g, yield 28%) as a light yellow powder.

Provenance & Evidence