N,O-dimethylhydroxylamine hydrochloride (TCI Chemicals)

Succinyl chloride (ACROS)

Triethylamine (Fisher Chemical)

Dichloromethane (Fisher Chemical)

In a three-necked round bottomed flask fitted with an argon inlet, a thermometer and an addition funnel, are successively placed N,O-dimethylhydroxylamine hydrochloride (24.00 g), dichloromethane (270 mL) and succinyl chloride (12.9 mL). The resulting suspension is cooled to 0°C under argon and triethylamine (67 mL) is added dropwise at such a rate that internal temperature remains below 10°C. When addition is completed, reaction mixture is stirred at 0°C for two hours. The solution is then allowed to warm to room temperature and then poured onto saturated aqueous sodium bicarbonate solution (150 mL). The obtained slurry is filtered on a glass sintered funnel and the layers are separated. Aqueous layer is extracted with dichloromethane (2×75 mL). Organic layers are combined, washed with brine (50 mL), dried over anhydrous sodium sulphate and concentrated. The compound is obtained as a light brown solid (15.31 g; 64%)

Weinreb amides are useful intermediates in the preparation of ketones by reacting with organometallic reagents. The compound so obtained is sufficiently pure to be used without further purification.

Harding, M. et al. J. Chem. Soc., Perkin Trans. 1, 2002, 2403-2413.