反应详情

A mixture of 45 parts of ethyl 4-[(2,6-dimethylphenyl)-imino]-1-piperidinecarboxylate, 0.3 parts of platinum dioxide in 160 parts of methanol is hydrogenated at normal pressure and at a temperature between 24°and 35° C. 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 distilled, to yield 30 parts of the oily free base of ethyl 4-[(2,6-dimethylphenyl)amino]-1-piperidinecarboxylate; bp. 148°-153° C. at 0.01 mm. pressure. From this distillate, the hydrochloride salt is prepared in the usual manner in 1,1'-oxybisethane. The precipitated solid salt is filtered off and dried, yielding 28.5 parts of ethyl 4-[(2,6-dimethylphenyl)amino]-piperidinecarboxylate hydrochloride; mp. 195.5° C.

1. customis hydrogenated at normal pressure and at a temperature between 24°and 35° C
2. filtrationThe catalyst is filtered off
3. customthe filtrate is evaporated
4. distillationThe oily residue is distilled