Tert-butyl 4-hydroxypiperidine-1-carboxylate → 1,1-Dimethylethyl 4-[[(4-amino-5-chloro-2,3-dihydro-7-benzofuranyl)carbonyl]oxy]-1-piperidinecarboxylate

Participants

Reaction Steps

A solution of 1,1-dimethylethyl 4-hydroxy-1-piperidinecarboxylate (4.02 g) and N,N-dimethyl-4-pyridinamine (3.7 g) in dichloromethane (200 ml) was stirred at room temperature. A solution of intermediate (7) (4.8 g) in CH2Cl2 (200 ml) was poured into the solution. The reaction mixture was stirred for 3 hours at room temperature. The mixture was washed with water, a 5% NaOH solution and again water. The organic layer was separated, dried over MgSO4, filtered and the solvent was evaporated. The residue (7.4 g) was purified by column chromatography over silica gel (eluent: CH2Cl2 /CH3OH 98/2). The pure fractions were collected and the solvent was evaporated, yielding 4.7 g of 1,1-dimethylethyl 4-[[(4-amino-5-chloro-2,3-dihydro-7-benzofuranyl)carbonyl]oxy]-1-piperidinecarboxylate (59%) (intermediate 8).

Provenance & Evidence