Potassium Carbonate → Oxalate

Participants

Reaction Conditions

Reaction Steps

To 100 ml. of ethanol was added 10.0 g. (0.033 mole) of 4-chloromethyl-1-methyl-3,3-diphenyl-2-pyrrolidinone, 5.8 g. (0.033 mole) of 4-hydroxy-4-phenylpiperidine and 13.8 g. (0.10 mole) of potassium carbonate (finely ground). The mixture was heated in a steel bomb with stirring in an oven for 48 hours at 200° C. After concentrating in vacuo, the residue was partitioned between dilute sodium hydroxide solution and chloroform. The chloroform was dried, filtered and concentrated in vacuo. The residue was dissolved in isopropanol and treated with oxalic acid, and the starting piperidine compound was obtained as an oxalate. The filtrate was concentrated in vacuo, and the residue was partitioned between dilute hydrochloric acid and ethyl acetate. The acid solution was made basic with dilute sodium hydroxide and was extracted with chloroform. The chloroform solution was dried (sodium sulfate), filtered and concentrated in vacuo. The residue was dissolved in hot isopropyl ether and treated with an equivalent amount of fumaric acid dissolved in isopropanol. The resulting salt was recrystallized from ethanol. The salt was triturated with acetonitrile to remove ethanol in the form of a solvate and dried. The salt (2.5 g., 14%) melted at 202°-205° C.

Provenance & Evidence