1-Methyl-4-oxonipecotic acid methyl ester hydrochloride 13049-77-9 3-Piperidinecarboxylic acid, 1-methyl-4-oxo-, methyl ester, hydrochloride N-Methyl-3-carbomethoxy-4-piperidone hydrochloride NIPECOTIC ACID, 1-METHYL-4-OXO-, METHYL ESTER, HYDROCHLORIDE NSC 113589