Hydrochloric Acid → 4-chloro-N-[3-[3-(hydroxymethylidene)-2-oxo-1H-indole-6-carbonyl]phenyl]-1-methylpyrazole-5-carboxamide

Participants

Reaction Conditions

Reaction Steps

4-Chloro-2-methyl-2H-pyrazole-3-carboxylic acid [3-(2-oxo-2,3-dihydro-1H-indole-6-carbonyl)-phenyl]-amide (0.250 g, 0.633 mmol) and ethyl formate (0.148 mL, 1.90 mmol) were dissolved in anhydrous ethanol (1.3 mL). The resulting solution was treated in dropwise fashion with a 21 wt % solution of sodium ethoxide in ethanol (2.48 mL, 3.17 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) causing the formation of a pale orange precipitate. The suspension was filtered yielding an orange solid as the pure 4-Chloro-2-methyl-2H-pyrazole-3-carboxylic acid [3-(3-hydroxymethylene-2-oxo-2,3-dihydro-1H-indole-6-carbonyl)-phenyl]-amide (0.187 g, 0.443 mmol, 70%).

Provenance & Evidence