To a solution of N-[(2E)-2-(1,2,6,7-tetrahydro-8H-cyclopenta[b]furo[3,2-d]pyridin-8-ylidene)ethyl]propanamide (65.0 mg, 0.252 mmol) in methanol (1.3 mL) was added palladium-carbon powder (13 mg), and the mixture was stirred at 50° C. for 6 hr under a hydrogen atmosphere. The catalyst was filtered off, and the filtrate was evaporated under reduced pressure. The residue was purified by silica gel column chromatography (ethyl acetate/hexane=50/50→100/0) to give the title compound (39.5 mg, yield 60%).
