反应详情

At 0° C., 2.7 g (68.0 mmol) of sodium hydride are added a little at a time to a solution of 33.0 g (68.0 mmol) of 4-bromo-N′-(diphenylmethylene)pentane hydrazide in 200 ml of tetrahydrofuran. The reaction mixture is stirred at room temperature for 16 h, and ethyl acetate/saturated aqueous NH4Cl solution is then added. The organic phase is separated off and the aqueous phase is extracted with 3×250 ml of ethyl acetate. The combined organic phases are dried over Na2SO4 and freed from the solvent under reduced pressure. Purification by column chromatography on silica gel (cyclohexane/ethyl acetate) gives 17.8 g (89%) of the desired product; log P(HCOOH): 2.73; 1H-NMR (ppm): δ (DMSO-d6)=1.22 (d, 3H), 2.05-2.15 (m, 4H), 3.86 (m, 1H), 7.24-7.26 (m, 2H), 7.40-7.43 (m, 4H), 7.48-7.53 (m, 4H); LC-MS: m/z=279 [M+H]+

1. customThe organic phase is separated off
2. extractionthe aqueous phase is extracted with 3×250 ml of ethyl acetate
3. dry with materialThe combined organic phases are dried over Na2SO4
4. customPurification by column chromatography on silica gel (cyclohexane/ethyl acetate)