反应详情

To a mixture of benzyl 4-cyanopiperidine-1-carboxylate (1.0 g, 4.0 mmol, Oakwood) in THF (50 mL) at about −78° C. was added LiHMDS (1.0 M solution in THF, 6.14 mL, 6.14 mmol) dropwise via syringe. The mixture was stirred for about 1 h. Paraformaldehyde (0.25 g, 8.2 mmol) was added in one portion and the mixture was stirred overnight at rt. The mixture was concentrated in vacuo and the residue was purified by preparative TLC (1:1 EtOAc/pet ether) to give benzyl 4-cyano-4-(hydroxymethyl)piperidine-1-carboxylate (0.45 g, 35%): LC/MS (Table 2, Method k) Rt=0.60 min; MS m/z: 274 (M+H)+.

1. stirringthe mixture was stirred overnight at rt
2. concentrationThe mixture was concentrated in vacuo
3. customthe residue was purified by preparative TLC (1:1 EtOAc/pet ether)