4-Piperidinecarboxylic acid, 4-(p-hydroxyphenyl)-1-methyl-, ethyl ester, hydrochloride 4-p-Hydroxyphenyl-4-carbethoxy-1-methylpiperidine hydrochloride 4220-06-8 70740-81-7 ISONIPECOTIC ACID, 4-(p-HYDROXYPHENYL)-1-METHYL-, ETHYL ESTER, HYDROCHLORIDE