Hydrochloric Acid → Methyl-2-dimethylcarbamoyl-1-(methoxycarbonylmethyl)piperidine-4-carboxylate

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Reaction Conditions

Reaction Steps

A mixture of compound 28 (55.4 g, 0.27 mmole), conc. HCl (16 ml) in MeOH (62 ml) was hydrogenated over platinum oxide (1 g) at 8 kg/cm2 for 24 hours. The catalyst was removed by filtration. The filtrate was concentrated under reduced pressure and the resulting oil was used without further purification. A mixture of crude intermediate compound hydrochloride, methyl bromoacetate (61 g, 0.4 mole) and K2CO3 (73.5 g, 0.53 mole) in toluene (200 ml) was heated at 70° C. for 3 hours. After cooling the reaction mixture, H2O (200 ml) was added and extracted with EtOAc (200 ml×2). The combined organic extracts were dried over MgSO4 and concentrated down. The crude oil was purified by silica gel chromatography EtOAc as eluent to give 29 (69.8 g, 0.26 mole, 97%).

Provenance & Evidence