Sodium hydride → methyl 2-(4-(tert-butoxycarbonyl)-(3S)-3-isobutylpiperazine-1-yl)benzoxazole-4-carboxylate

Participants

Reaction Steps

To a solution of 1-tert-butyloxycarbonyl-(2S)-2-isobutylpiperazine (384 mg, 1.6 mmol) in DME (10 mL) was added NaH (70 mg of 60% suspension in mineral oil, 1.6 mmol) and the mixture was stirred for 1 h at room temperature. Methyl 2-chlorobenzoxazole-4-carboxylate (368 mg, 1.6 mmol) was added to the reaction mixture and suspension formed was stirred at room temperature for 17 h. The reaction mixture was quenched with CH3OH (10 mL), silica gel (15 mL) was added, and solvent removed under reduced pressure. The mixture was purified by column chromatography ((silica gel, 0 to 80% EtOAc in CH2Cl2) to afford methyl 2-(4-(tert-butoxycarbonyl)-(3S)-3-isobutylpiperazine-1-yl)benzoxazole-4-carboxylate (219 mg, 32%) as a clear oil: 1H NMR and MS consistent.

Provenance & Evidence