Isobutyl chloroformate → HCID 67506537, compound

Participants

Reaction Steps

3-{(2S,4S)-1-tert-Butoxycarbonyl-4-[4-(5-carboxy-2-benzoxazolyl)piperidino]-2-pyrrolidinylcarbonyl}-1,3-thiazolidine [product of Example 310 (1), 1.06 g] was dissolved in tetrahydrofuran (5 mL), and triethylamine (0.279 mL) and isobutyl chlorocarbonate (0.263 mL) were added thereto under ice-cooling. The mixture was stirred at room temperature for 30 min. A solution of 7 mol/L ammonia-methanol (1 mL) was added to the reaction mixture, and the mixture was stirred at room temperature for 15 hr. Water was added to the reaction mixture, and the mixture was extracted with chloroform. The extract was dried and concentrated under reduced pressure. The residue was purified by silica gel chromatography to give 3-{(2S,4S)-1-tert-butoxycarbonyl-4-[4-(5-carbamoyl-2-benzoxazolyl)piperidino]-2-pyrrolidinylcarbonyl}-1,3-thiazolidine (345 mg) as a white powder.

Provenance & Evidence