Ethylpiperidine-3-carboxylatehydrochloride

3-(ethoxycarbonyl)piperidinium hydrochloride; To a solution of piperidine-3-carboxylic acid (10.7 g, 83 mmol) in ethanol (40 mL) was added thionyl chloride (22.5 mL) at 0° C. dropwise, the reaction mixture was refluxed overnight. Then the mixture was evaporated at reduced pressure to give 3-(ethoxycarbonyl)piperidinium hydrochloride. (13 g, Y: 100percent). LC-MS (ESI) (m/z): 158 (M+1)To a stirring solution of piperidine-3-carboxylic acid (SM) (20 g, 154.8 mmol) in EtOH was added thionyl chloride (45 ml, 619.2 mmol) at 0 °C and heated to reflux for 24 h. The reaction mixture was warmed to RT and concentrated under reduced pressure. Crude material was triturated with diethyl ether and dried to afford compound 1 .HC1 salt (29 g, 99 percent) as thicksyrup.‘H-NMR: (400 MHz, DMSO-d6): ö 9.40 (s, 1H), 9.25 (s, 1H), 4.09 (q, J = 7.2 Hz, 2H), 3.32.3.13 (m, 2H), 2.94-2.75 (m, 3H), 1.99-1.96 (m, 1H), 1.77-1.71 (m, 2H), 1.60-1.58 (1H), 1.16 (t, J = 7.2 Hz, 3H).LCMS (ES): mlz 157.3 [MjExample 91A