Citric Acid → 3,4,5-Trimethoxy-N-methycinnamohydroxamic acid

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

Triethylamine (3.07 ml, 22 mmol) was added to a stirred solution of 3,4,5-trimethoxycinnamic acid (4.76 g, 20 mmol) in N,N-dimethylformamide (30 ml). The resulting solution was cooled to -12° C., and ethyl chloroformate (2.00 ml, 21 mmol) was added dropwise with stirring. After 15 minutes, solid N-methylhydroxylamine hydrochloride (1.84 g, 22 mmol) was added, followed by triethylamine (3.2 ml, 23 mmol). The mixture was allowed to warm to room temperature, stirred overnight, and poured into 150 ml of 1% aqueous citric acid. The mixture was extracted twice with ethyl ether, and the combined extracts washed successively with water and brine, then dried over MgSO4, filtered, and evaporated. The residue was recrystallized from ethyl acetate to provide 1.82 g (34% yield) of the titled compound as colorless crystals, mp 169°-170° C.

Herkunft & Nachweise