Hydrochloric Acid → N-(piperidin-4-yl)pyridin-3-amine

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Reaction Steps

A mixture of 20 parts of N-[1-(phenylmethyl)-4-piperidinyl]-3-pyridinamine, 160 parts of methanol, 30 parts of water and 12 parts of a concentrated hydrochloric acid solution is hydrogenated at normal pressure and at a temperature between 22°-39° C., in the presence of 7 parts of palladium-on-charcoal catalyst 10%. After the calculated amount of hydrogen is taken up, hydrogenation is stopped. The catalyst is filtered off and the filtrate is evaporated. The oily residue is dissolved in water. This solution is rendered alkaline with ammonium hydroxide, saturated with solid potassium carbonate and then extracted with methylbenzene. The extract is dried over potassium carbonate and evaporated. The solid residue is recrystallized from a mixture of 40 parts of benzene and 32 parts of 1,1'-oxybisethane, yielding 3 parts of N-(4-piperidinyl)-3-pyridinamine; mp. 127°-129° C.

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