2,5-Dimethyl-2H-pyrazole-3-carbonyl chloride → 2,5-Dimethyl-2H-pyrazole-3-carboxylic acid [4-(2-oxo-2,3-dihydro-1H-indole-6-carbonyl)-phenyl]-amide

Participants

Reaction Steps

A dry 25 mL flask was charged with 2,5-Dimethyl-2H-pyrazole-3-carbonyl chloride (0.820 g, 5.15 mmol) and THF (10 mL). 6-(4-Amino-benzoyl)-1,3-dihydro-indol-2-one (as prepared in Example 15, 1.00 g, 3.97 mmol) was added to the THF solution of the acid chloride, and the mixture was allowed to reflux for 4 h. The reaction mixture was then allowed to cool to room temperature. The room temperature reaction mixture was concentrated in vacuo, and the crude residue was dissolved in EtOH (5 mL). The ethanolic solution was treated with 1M NaOH(aq) (2 mL) and stirred for 30 min. The basic solution was acidified to a pH of 1 with 1M HCl(aq) yielding a tan precipitate. The solids were filtered to afford the pure 2,5-Dimethyl-2H-pyrazole-3-carboxylic acid [4-(2-oxo-2,3-dihydro-1H-indole-6-carbonyl)-phenyl]-amide (1.35 g, 3.60 mmol, 91%).

Provenance & Evidence