Yield:-

Reaction Conditions:

palladium in methanol;ethanol;

Steps:

10.a (a)

(a) 4-Ethoxycarbonylaminopiperidine 16 g (61 mmol) of 1-benzyl-4-ethoxycarbonylaminopiperidine were hydrogenated in 240 ml of methanol and 80 ml of 10% strength methanolic hydrochloric acid on 4 g of palladium-on-charcoal (10%) at 45° C. in a shaking vessel for 90 minutes. The catalyst was filtered off with suction, the solvent was evaporated off, the residue was dissolved in 400 ml of ethanol and the solution was neutralized with ethanolic NaOH. The NaCl which had precipitated out was filtered off and the filtrate was concentrated. Yield: 10.5 g; melting point 192°-194° C.

References:

US4918073,1990,A