1,4-Dioxane hydrochloride → Ethyl 2-[(3S,4R)-3-amino-4-{[(4-chloro-5-ethyl-1H-imidazol-2-yl)carbonyl]amino}piperidin-1-yl]-1,3-benzothiazole-7-carboxylate

Participants

Reaction Steps

A 4 N hydrochloric acid/1,4-dioxane solution (3 mL) was added to ethyl 2-[(3S,4R)-3-[(tert-butoxycarbonyl)amino]-4-{[(4-chloro-5-ethyl-1H-imidazol-2-yl)carbonyl]amino}piperidin-1-yl]-1,3-benzothiazole-7-carboxylate obtained in Example (202d) (121 mg, 0.210 mmol), and the mixture was stirred at room temperature for one hour. The reaction solution was concentrated under reduced pressure. Saturated aqueous sodium bicarbonate solution was added to the resulting residue, followed by extraction with ethyl acetate. The organic layer was washed with brine and dried over anhydrous sodium sulfate. The filtrate was concentrated. The resulting residue was purified by silica gel column chromatography (eluent: chloroform:methanol=10:1 v/v) to obtain 100 mg of the title compound (100%) as a colorless solid.

Provenance & Evidence