78056-60-7

78056-59-4

78056-60-7

General procedure for the synthesis of N-acetylpiperidine-4-acetic acid from ethyl 1-acetyl-4-piperidineacetate (CAS: 78056-59-4): to a stirred solution of 92 parts of ethyl 1-acetyl-4-piperidineacetate in 200 parts of ethanol was slowly added 60 parts of a 30% sodium hydroxide solution dropwise. After the addition was completed, the reaction mixture was continued to be stirred in a warm water bath for 2 hours. Subsequently, the reaction mixture was poured into water and the entire mixture was filtered using a hyflo filter aid. The clarified filtrate was concentrated to one-third of the original volume and then the concentrate was acidified with dilute hydrochloric acid solution. The product was crystallized under cooling conditions. Finally, the crystallized product was filtered and dried to give 29 parts (36.5% yield) of 1-acetyl-4-piperidineacetic acid with a melting point of 124.1 °C.