Hydrochloric Acid → 2-ethyl-N-[4-[[3-(hydroxymethylidene)-2-oxo-1H-indol-5-yl]methyl]phenyl]-5-methylpyrazole-3-carboxamide

Participants

Reaction Conditions

Reaction Steps

2-Ethyl-5-methyl-2H-pyrazole-3-carboxylic acid [4-(2-oxo-2,3-dihydro-1H-indol-5-ylmethyl)-phenyl]-amide (0.140 g, 0.374 mmol) and ethyl formate (0.060 mL, 0.816 mmol) were dissolved in anhydrous ethanol (0.250 mL). The resulting solution was treated in dropwise fashion with a 21 wt % solution of sodium ethoxide in ethanol (0.42 mL, 1.12 mmol). This reaction mixture was heated at 78° C. for 0.5-1 h, producing a viscous, dark reddish colored oil. Subsequently, the reaction mixture was cooled to room temperature, and then the reaction pH was adjusted to pH 3 with dropwise addition of 1M HCl(aq) causing the formation of a grey precipitate. The suspension was filtered yielding a grey solid as the pure product (0.070 g, 0.175 mmol, 47%).

Provenance & Evidence