HCID 22452728, compound → HCID 135833323, compound

Participants

Reaction Conditions

Reaction Steps

Titanium tetrachloride (0.85 ml) was added dropwise to a solution of the compound (1.0 g) obtained in Example 50A in dichloromethane (35 ml) under ice-cooling, and the mixture was stirred at 0° C. for 1.5 hours. The reaction mixture was poured over ice-water, and the mixture was extracted with dichloromethane. The dichloromethane layer was washed successively with an aqueous saturated solution of sodium bicarbonate and water, dried (MgSO4) and concentrated under reduced pressure. The residue was subjected to silica gel column chromatography and eluted with ethyl acetate-chloroform (1:1, v/v) to yield ethyl 2-diethylaminomethyl-4-(4-hydroxy-3-methoxyphenyl)thieno[2,3-b:5,4-c']dipyridine-3-carboxylate (0.41 g, 44%), which was then recrystallized from ethyl acetate to yield colorless prismatic crystals having a melting point of 179 to 181° C.

Provenance & Evidence