Hydrochloric Acid → (4S,7S,10aS)-4-(tert-butoxycarbonylamino)-5-oxooctahydro-2H-pyrido[2,1-b][1,3]thiazepine-7-carboxylic acid

Participants

Reaction Steps

To a solution of (4S,7S,10aS)-methyl 4-(tert-butoxycarbonylamino)-5-oxooctahydro-2H-pyrido[2,1-b][1,3]thiazepine-7-carboxylate (0.139 g, 0.387 mmol) in MeOH (6 mL) was added NaOH (1 N in water, 387 μL, 0.387 mmol). The mixture was stirred at rt overnight. HPLC showed only 20% conversion. Additional NaOH (1 N in water, 387 μL, 0.387 mmol) was added and the reaction was stirred for an additional 3 days. The mixture was cooled with ice-water and the reaction was carefully neutralized with aqueous 1 N HCl to pH<7. The reaction was extracted with DCM. The organic layer was washed with water, dried over MgSO4, filtered and concentrated to give (4S,7S,10aS)-4-(tert-butoxycarbonylamino)-5-oxooctahydro-2H-pyrido[2,1-b][1,3]thiazepine-7-carboxylic acid (133 mg, 0.386 mmol, 99% yield) as a white solid.

Provenance & Evidence