反应详情

2 g (0.019 mol) of tert-butylnitrite are added dropwise to 30 ml of ethyl acetate saturated with dry hydrogen chloride at −10° C. and the mixture is stirred at this temperature for 15 minutes. 1.6 g (0.0098 mol) of benzofuran-3-one O-methyl oxime dissolved in 5 ml of ethyl acetate are then added at −10° C., the temperature is allowed to rise to 0° C. and the mixture is stirred at this temperature for 30 minutes. The product which has crystallized out is filtered off and 1.08 g of crystalline benzofuran-2,3-dione 3-(O-methyl oxime) 2-oxime are obtained as mixture of two stereoisomers which, according to the HPLC analysis, comprises isomer B to the extent of 54.7% (56% of theory) and isomer A to the extent of 42.9%.

1. additionare then added at −10° C.
2. customto rise to 0° C.
3. stirringthe mixture is stirred at this temperature for 30 minutes
4. customThe product which has crystallized out
5. filtrationis filtered off