Hydrochloric Acid → Ethyl 3-methylpiperidine-3-carboxylate

Participants

Reaction Conditions

Reaction Steps

Ethyl-5-chloro-2-cyano-2-methylpentanoate (DE 31 39 301 A1) (10.43 g, 51.2 mmol), PtO2 hydrate (1.16 g) and concentrated HCl (12.5 ml) in absolute EtOH (125 ml) were stirred and heated at 40° C. under hydrogen at normal pressure for 2 h. The cooled solution was filtered. After evaporation of the solvent, the residue was dissolved in absolute EtOH (125 ml). The solution was cooled with an ice-water bath and triethylamine (9.8 g, 96.8 mmol) was added. After the addition the mixture was stirred at RT for 16 h under nitrogen atmosphere. The solvent and triethylamine were evaporated, and the residue was dissolved in DCM (100 ml) and extracted with 1 M HCl (3×100 ml). After separating the layers, ice (150 g) and 5 M NaOH (100 ml) were added to the aqueous layer, which was then extracted with DCM (3×60 ml). The combined extracts were dried, filtered and evaporated to dryness followed by vacuum distillation (bp. 62-65° C./2 mbar) to give 6.0 g of the title compound as a colorless liquid.

Provenance & Evidence