5166-67-6

122-51-0

71962-74-8

5166-67-6

The general procedure for the synthesis of ethyl 1-methyl-3-piperidinecarboxylate from triethyl orthoformate and ethyl crotonate is as follows: in an autoclave, a 1 molar concentration of catalyst based on the molar amount of amine is added, and after displacing the air in the autoclave with argon, 0.1 moles of amine and 0.11-0.3 moles of o-carboxylic acid ester dissolved in a 10 ml solution in methanol (or ethanol) are added, as well as 0.5 ml of 0.2 M anhydrous p-toluene benzenesulfonic acid solution in methanol (or ethanol). The reaction mixture was heated to 120°C and charged with hydrogen gas to a pressure of 40 bar. The reaction mixture was stirred continuously at a constant pressure until the absorption of hydrogen ceased (reaction time of about 0.2-6 hours). After completion of the reaction, the catalyst was removed by filtration and the filtrate was distilled to purify the target product.