Acetic Acid → HCID 69479141, 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 1 hour. 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 20 minutes and then concentrated under reduced pressure. The residue was dissolved in methanol (5 ml). To the solution, 4-trifluoromethylbenzaldehyde (0.164 g, 0.945 mmol), sodium cyanotrihydroborate (0.099 g, 1.57 mmol) and acetic acid (0.09 ml, 1.57 mmol) were added followed by stirring at room temperature for 4 hours. The reaction mixture was concentrated under reduced pressure. To the residue, water was added, and the solution was extracted with methylene chloride. The organic phases were combined, washed with 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 (methylene chloride/methanol=20/1) and recrystallized from isopropyl alcohol to afford (S)-N-[1-(2-methyl-6-nitro-2,3-dihydroimidazo[2,1-b]oxazol-2-ylmethyl)piperidin-4-yl]-4-trifluoromethylbenzylamine (0.078 g, yield 22%) as a light yellow powder.

Provenance & Evidence