Hydrochloric Acid → 2,5-Dimethoxy-N-methylcinnamohydroxamic acid

Participants

Reaction Conditions

Reaction Steps

A solution of 2,5-dimethoxycinnamic acid (2.08 g, 10 mmol), oxalyl chloride (0.96 ml, 11 mmol) and N,N-dimethylformamide (two drops) in 25 ml dichloromethane was stirred for 20 minutes. The resulting solution was evaporated to leave a yellow solid, which was then dissolved in 10 ml of acetone. This solution was added slowly to a stirred mixture of water (20 ml), sodium carbonate (2.5 g, 24 mmol), and N-methylhydroxylamine hydrochloride (1.06 g, 12.7 mmol), cooled to 5° C. The resulting mixture was stirred for 20 minutes, then poured into excess 1M hydrochloric acid and extracted twice with ethyl acetate. The extracts were washed wth water and 1N NaHCO3, dried over MgSO4, and evaporated to leave an orange oil. Chromatography on silica gel with 7:3 ethyl acetate-hexane provided 0.96 g (40% yield) of the named compound, mp 111°-112° C., after recrystallization from hexane-1,2-dichloroethane.

Provenance & Evidence