Hydrochloric Acid → 2-(Pyrrolidin-3-yl)pyridine

Participants

Reaction Conditions

Reaction Steps

To 2-(1-benzylpyrrolidin-3-yl)pyridine enantiomer 1 a1-64 (10.01 g, 41.96 mmol, 1 eq) in methanol (340 ml) is added Pd/C (5%, 1.98 g). A solution of ammonium formate (10.69 g, 167.83 mmol, 4 eq) in water (55 ml) is then added dropwise over a period of 10 minutes. The reaction mixture is heated for 45 mins at 68° C., then cooled to room temperature. The catalyst is filtered off using Celite, washed with methanol (60 ml) and the pooled filtrates evaporated to dryness. The residue is retaken in methanol (50 ml) and evaporated again. Dichloromethane (100 ml) is added to the residue, the solid obtained is filtered, washed with dichloromethane (30 ml) and the pooled filtrates are evaporated to dryness to give a yellow oil. This oil is dissolved in isopropanol (60 ml) and a mixture of isopropanol (21 ml)/aqueous HCl 6N (21 ml, 3 eq) is added slowly over a period of 15 minutes to the solution. The mixture is stirred at room temperature overnight, the precipitate obtained is filtered, washed with isopropanol (10 ml) and dried under vacuum for 4 hours at 40° C. to afford 7.90 g of 2-(pyrrolidin-3-yl)pyridine enantiomer 1 dihydrochloride a1-66. Yield: 85%.

Provenance & Evidence