反应详情

6-Cyano-3,4-dihydro-2,2-dimethyl-3,4-epoxy-2H-benzo[b]pyran and 2-piperidone were stirred in dimethyl sulphoxide under nitrogen at room temperature. Sodium hydride (81% dispersion in mineral oil) was added during 5 mins. and the reaction stirred for a further 6 hours. Addition of water, extraction with ethyl acetate, drying of the organic phase with magnesium sulpate, filtration, evaporation and recrystallisation from ethyl acetate gave 6-cyano-3,4-dihydro-2,2-dimethyl-trans-4-(2-oxo-1-piperidinyl)-2H-benzo[b]pyran-3-ol was prepared, as crystals of m.p. 155° C.

1. dry with materialdrying of the organic phase with magnesium sulpate, filtration, evaporation and recrystallisation from ethyl acetate