Benzoylhydrazine → N'-benzoyl-3-iodo-1-tosyl-1H-indole-5-carbohydrazide

Participants

Reaction Steps

To a stirring suspension of 3-iodo-1-tosyl-1H-indole-5-carboxylic acid (515 mg, 1.17 mmol) and benzohydrazide (159 mg, 1.167 mmol) in THF (10 mL) was added N-ethyl-N-isopropylpropan-2-amine (0.51 mL, 2.92 mmol) followed by HATU (488 mg, 1.28 mmol) in one portion and the solution was stirred at RT for 2 h. The reaction was quenched with 20 mL of ice cold H2O and extracted with EtOAc (2×50 mL). The organic layer was washed with 10 mL of sat. NaHCO3 followed by brine, and dried over Na2SO4. It was concentrated to about 5 mL and the precipitated solid was filtered, rinsed with EtOAc (2×2 mL). The white solid was collected and dried in a vacuum oven for 5 h at 40° C. affording N′-benzoyl-3-iodo-1-tosyl-1H-indole-5-carbohydrazide (305 mg, 47%) as an off-white crystalline solid. MS (ESI, pos. ion) m/z: 560.0 (M+1). 1H NMR (400 MHz, DMSO-D6) δ ppm 10.67 (1H, s), 10.52 (1H, s), 8.19 (1H, s), 8.08 (1H, d, J=8.4 Hz), 78.03-7.88 (6H, m), 7.67-7.49 (3H, m), 7.42 (2H, d, J=8.2 Hz), 2.33 (3H, s).

Provenance & Evidence