反应详情

Benzyl chloroformate (4.75 mL, 33.1 mmol) was added dropwise to a solution of 4-phenyl-4-piperidinecarboxylic acid p-methylbenzenesulfonate (10.0 g, 26.5 mmol) in 1M sodium hydroxide (200 mL)/dichloromethane (100 mL). After 2 hours the reaction mixture was made acidic with 1M hydrochloric acid (pH=3), the organic layer was separated and the aqueous layer extracted with ethyl acetate (3×100 mL). The organic layers were collected, concentrated and crude product washed with water (3×50 mL) to give 8.52 g of 4-phenyl-piperidine-1,4-dicarboxylic acid monobenzyl ester. LRMS m/z 340.2 (M+H)+.

1. customthe organic layer was separated
2. extractionthe aqueous layer extracted with ethyl acetate (3×100 mL)
3. customThe organic layers were collected
4. concentrationconcentrated
5. washcrude product washed with water (3×50 mL)