反应详情

Diethyl azodicarboxylate (1.86 g) was added dropwise to a solution of triphenylphosphine (2.81 g), 4-chloro-2-hydroxybenzonitrile (1.49 g) and the product from step (a) (1.79 g) in tetrahydrofuran (5 ml) and toluene (60 ml) at 0° C. and stirred at 0° C. for 4hand at 20° C. for 18 h. The solvent was removed in vacuo and the residue was purified by chromatography on silica eluting with hexane-diethyl ether (4:1) to give the title compound as a colourless oil (2.80 g).

1. customThe solvent was removed in vacuo
2. customthe residue was purified by chromatography on silica eluting with hexane-diethyl ether (4:1)