反应详情

A mixture of 1.3 g (4.2 mmol) of 3,4-dihydro-2,5,7,8-tetramethyl-2-(2-phenylethynyl)-2H-1-benzopyran-6-ol (Example 1), 0.3 g of 5 % palladium on carbon. 50 ml of tetrahydrofuran and 50 ml ethanol was hydrogenated at atmospheric pressure for 4 hours. The catalyst was filtered off and the filtrate was evaporated. Crystallization of the residue from hexane yielded 0.9 g (69 %) of colorless crystals with m.p. 96°-98°.

1. filtrationThe catalyst was filtered off
2. customthe filtrate was evaporated
3. customCrystallization of the residue from hexane