Sodium Bicarbonate → 3,3-Dimethylindolin-5-ol

Participants

Reaction Steps

A solution of 1-acetyl-3,3-dimethylindolin-5-ol (150 mg, 0.73 mmol) in 1.5 mL of 6 M HCl was stirred at 105° C. for 17 h. After the reaction mixture was diluted with toluene, the separated aqueous layer was neutralized by saturated NaHCO3 aqueous solution, and extracted with ethyl acetate. The extract was washed with brine, and dried over MgSO4. After filtration, the filtrate was concentrated in vacuo to obtain crude 3,3-dimethylindolin-5-ol (128 mg). To a solution of the above product in a 1:1 solution (2.0 mL) of acetic acid and tetrahydrofuran was added benzaldehyde (0.15 mL, 0.15 mmol) at room temperature. After being stirred at the same temperature for 1 h, sodium cyanoborohydride (10.4 mg, 0.165 mmol) was added with additional stirring for 1 h. After the reaction mixture was neutralized by saturated NaHCO3 aqueous solution, the reaction mixture was diluted with ethyl acetate. The separated organic layer was washed with brine, and dried over MgSO4. After filtration, the filtrate was concentrated in vacuo, and the residue was purified with silica gel column chromatography (hexane/ethyl acetate=90/10 to 80/20) to obtain the title compound (108 mg, 56%).

Provenance & Evidence