Coumaranone → benzofuran-3-one O-methyl oxime

Participants

Reaction Steps

6.7 g (0.05 mol) of benzofuran-3-one are boiled under reflux with 4.2 g (0.05 mol) of O-methylhydroxylamine hydrochloride and 4.1 g (0.05 mol) of sodium acetate in 50 ml of methanol for 3 hours. The solvent is distilled off in vacuo and the reaction mixture is poured onto water and extracted with ethyl acetate. The organic phase is washed with saturated aqueous sodium carbonate solution. The organic phase is dried over sodium sulphate and the solvent is distilled off in vacuo. 7.27 g (89.2% of theory) of crude benzofuran-3-one O-methyl oxime are obtained. For analysis, it is distilled under 2 torr at 70° C. in a bulb tube. An oil is obtained which, both according to the NMR analysis and according to the HPLC analysis, comprises two stereoisomers (79% of isomer B and 21% of isomer A).

Provenance & Evidence