Dichloromethane → Benzyl hydroxycarbamate

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

Hydroxylamine hydrochloride (8.31 g, 120 mmol) is dissolved in water (200 mL) followed by the introduction of sodium bicarbonate (17.7 g, 211 mmol). Then CH2Cl2 (200 mL) is added to the solution and resulting the mixture is cooled in an ice bath to 0-4° C. Benzyl chloroformate (16.7 mL, 117 mmol) is added with vigorous stirring while maintaining the temperature below 4° C. After addition is complete the reaction mixture is left to stir for 2 h. The biphasic reaction mixture is transferred into a separating funnel and CH2Cl2 is added until the organic phase clarified. The aqueous phase is extracted with CH2Cl2 (3×100 mL) and then washed with brine, dried over MgSO4 and concentrated to give a colourless solid. Flash column chromatography (silica gel, CH2Cl2 then ethyl acetate/petroleum spirits 3:7 then 1:0) affords 13.7 g (70%) of 51 as a colourless solid along with 4.60 g (13%) of 52 as a colourless oil. Spectroscopic data are identical to those reported above.

Herkunft & Nachweise