Hydrochloric Acid → 7-hydroxy-2-methyl-2-phenylthiazolo[3,2-a]indol-3(2H)-one

Participants

Reaction Steps

To a solution (13 ml) of 1,3-dihydro-5-hydroxyindol-2-thione (1.26 g) and ethyl 2-bromo-2-phenylpropionate (1.88 g) in DMF, an aqueous 2N sodium hydroxide solution (7.3 ml) was added dropwise under ice cooling, and the mixture was stirred at room temperature for 3 hours. The reaction mixture was diluted with water, made acidic by adding 6N hydrochloric acid, and extracted with ethyl acetate. The organic layer was washed with water, and a saturated aqueous sodium chloride solution, and was dried over sodium sulfate. The solvent was evaporated under reduced pressure, and the residue was purified by silica gel column chromatography (diluting solvent: methylene chloride) to give 1.77 g (yield: 81/9 %) of 7-hydroxy-2-methyl-2-phenylthiazolo[3,2-a]indol-3(2H)-one.

Provenance & Evidence