反应详情

温度

78 °C

Methyl-3-(2-oxo-2,3-dihydro-1H-indol-6-ylsulfanyl)-benzamide (as prepared in step 1 above; 0.71 g, 0.239 mmol) and ethyl formate (0.058 mL, 0.717 mmol) were dissolved in anhydrous ethanol (0.5 mL). The resulting solution was treated in dropwise fashion with a 21 wt % solution of sodium ethoxide in ethanol (0.446 mL, 1.20 mmol). This reaction mixture was heated at 78° C. for 1 h, producing a black oil. Subsequently, the reaction mixture was cooled to room temperature, and then the reaction pH was adjusted to pH=1 with dropwise addition of 1M HCl(aq). The reaction mixture was diluted with EtOAc (15 mL) and washed with brine (3×15 mL). The combined organics were then dried over Na2SO4, filtered and concentrated in vacuo. The crude residue was purified via flash silica gel chromatography (10% MeOH in CHCl3) affording the title compound in 26% yield (0.020 g, 0.0621 mmol).

1. customproducing a black oil
2. temperatureSubsequently, the reaction mixture was cooled to room temperature
3. washwashed with brine (3×15 mL)
4. dry with materialThe combined organics were then dried over Na2SO4
5. filtrationfiltered
6. concentrationconcentrated in vacuo
7. customThe crude residue was purified via flash silica gel chromatography (10% MeOH in CHCl3)