Acetic Acid → HCID 69481699, compound

Participants

Reaction Steps

A mixture of tert-butyl 4-(2-methyl-6-nitro-2,3-dihydroimidazo[2,1-b]oxazol-2-ylmethyl)-homopiperazin-1-carboxylate prepared in Example 645 (346 mg, 0.91 mmol) and trifluoroacetic acid (10 ml) was stirred at room temperature overnight. The reaction mixture was concentrated under reduced pressure, and the residue was dissolved in methylene chloride (10 ml). To the solution, triethylamine (0.27 ml, 1.96 mmol) was added. The solution was concentrated under reduced pressure, and the residue was dissolved in methanol (10 ml). To the solution, 4-phenylbenzaldehyde (496 mg, 2.72 mmol), sodium cyanotrihydroborate (171 mg, 2.72 mmol) and acetic acid (0.17 ml, 2.72 mmol) were added in this order followed by stirring at room temperature overnight. The reaction mixture was poured into a saturated sodium hydrogencarbonate solution, then extracted with methylene chloride. The organic phase was dried over magnesium sulfate and then filtered. The filtrate was concentrated under reduced pressure, and the residue was purified by silica gel column chromatography (methylene chloride/ethyl acetate=5/1) to afford 2-[4-(biphenyl-4-ylmethyl)homopiperazin-1-ylmethyl]-2-methyl-6-nitro-2,3-dihydroimidazo[2,1-b]oxazole (251 mg, yield 62%) as a white powder.

Provenance & Evidence