Lawesson's reagent → Ethyl 5-{7-(benzyloxy)-5-[4-(methylsulfonyl)phenoxy]-1H-indol-2-yl}-1,3,4-thiadiazole-2-carboxylate

Participants

Reaction Conditions

Reaction Steps

Ethyl [2-({7-(benzyloxy)-5-[4-(methylsulfonyl)phenoxy]-1H-indol-2-yl}carbonyl)hydrazino](oxo)acetate (420 mg) was dissolved in tetrahydrofuran (15 mL), Lawesson's reagent (308 mg) was added, and the mixture was stirred at 50° C. for 5 hr. Lawesson's reagent (300 mg) was added again to the reaction solution, and the mixture was further stirred at 50° C. for 1 hr. The reaction solution was concentrated under reduced pressure. The residue was subjected to silica gel column chromatography (ethyl acetate:hexane=10:90-40:60, volume ratio), and the obtained yellow oil was crystallized from methanol to give the title compound (310 mg, yield 74%) as pale-yellow crystals. The obtained crystals was recrystallized from ethyl acetate-diethyl ether to give pale-yellow crystals. melting point 194-195° C. MS 550 (MH+).

Provenance & Evidence