反应详情

A solution of 4.9 g (0.040 mol) 4-hydroxy-benzaldehyde, 10.0 g (0.050 mol) 4-hydroxy-piperidine-1-carboxylic acid tert-butyl ester (analogously to K. L. Bhat, D. M. Flanagan, M. M. Jouille, Synth. Commun. 1985, 15, 587-598) and 13.1 g (0.050 mol) triphenylphosphine in 200 ml tetrahydrofuran is mixed at 5° C. with 7.9 ml (0.050 mol) azodicarboxylic acid diethyl ester and stirred for 24 hours at room temperature. After concentration the residue is purified by chromatography on a silica gel column (mobile solvent: isohexane/ethyl acetate 8:2, 7:3). After concentrating the appropriate column fractions one obtains 18.4 g (85%) of the title compound as a yellowish solid substance. Melting point. 63-64° C.; EI-MS: 305 (M+).

1. concentrationAfter concentration the residue
2. customis purified by chromatography on a silica gel column (mobile solvent: isohexane/ethyl acetate 8:2, 7:3)
3. concentrationAfter concentrating the appropriate column fractions one