反应详情

A stirred mixture of 5-{4-[2-(5-methyl-2-phenyl-4-oxazolyl)-2-oxoethoxy]benzylidene}-2,4-thiazolidinedione (1.0 g), Pd-black (3 g) and dioxane (100 ml) was hydrogenated at 40° C. and at atmospheric pressure. After 4 hours, another Pd-black (3 g) was added and hydrogenation was continued for 4 hours. The catalyst was filtered off and the filtrate was concentrated to yield 5-{4-[2-(5-methyl-2-phenyl-4-oxazolyl)-2-oxoethoxy]benzyl}-2,4-thiazolidinedione (the same compound as that obtained in Example 48) as crystals (0.95 g, 94.1%). Recrystallization from ethyl acetate-hexane gave colorless needles, m.p. 168°-169° C.

1. customwas hydrogenated at 40° C. and at atmospheric pressure
2. waithydrogenation was continued for 4 hours
3. filtrationThe catalyst was filtered off
4. concentrationthe filtrate was concentrated