Isopropanol → HCID 86668480, compound

Participants

Reaction Steps

The compound (2.22 g, 6.43 mmol) obtained in step A, isopropanol (0.65 ml, 8.46 mmol), and triphenylphosphine (1.85 g, 7.05 mmol) were dissolved in tetrahydrofuran (50 ml) and the mixture was stirred under ice-cooling. Thereto was slowly added 40% diisopropyl azodicarboxylate-toluene solution (5 ml), and the mixture was stirred at the same temperature for 1 hr. The reaction mixture was concentrated under reduced pressure and diluted with diethyl ether, and the precipitated colorless solid was filtered off. The mother liquor was concentrated under reduced pressure and the obtained oil was purified by silica gel column chromatography (ethyl acetate-hexane) to give tert-butyl[2-{isopropyl[(2-nitrophenyl)sulfonyl]amino}ethyl]carbamate (3.75 g) as a colorless crude oil. This was dissolved in dichloromethane (10 ml), 4N hydrochloric acid-dioxane solution 10 ml) was added at room temperature and the mixture was stirred for 1 hr. The reaction mixture was diluted with diethyl ether, and the mixture was extracted with water. The aqueous layer was alkalified with aqueous sodium hydroxide solution, extracted with dichloromethane, dried over sodium sulfate, the insoluble material was filtered off, and the solution was concentrated under reduced pressure to give the title compound (1.39 g, yield 75%) as a yellow oil.

Provenance & Evidence