Cyclopropanecarbohydrazide → N'-(cyclopropanecarbonyl)-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 (1.944 g, 4.41 mmol) and cyclopropanecarbohydrazide (0.441 g, 4.41 mmol) (Enamine) in THF (40 mL) was added N-ethyl-N-isopropylpropan-2-amine (1.919 mL, 11.01 mmol) (Sigma-Aldrich) followed by HATU (1.843 g, 4.85 mmol) (Oakwood Products) in one portion and the solution was stirred at RT for 45 min. Several ice chunks were added to the mixture followed by H2O (75 mL). The mixture was extracted with EtOAc (2×100 mL). The organic layer was washed with 50 mL of sat. NaHCO3, then brine, dried over MgSO4, filtered, and concentrated to a volume of about 50 mL of EtOAc. A precipitate formed and was isolated by filtration. The filter cake was washed with EtOAc (2×10 mL) to give N′-(cyclopropanecarbonyl)-3-iodo-1-tosyl-1H-indole-5-carbohydrazide (1.13 g, 2.159 mmol, 49.0%) as an off-white solid. MS (ESI, pos. ion) m/z: 523.8 (M+1). 1H NMR (400 MHz, DMSO-d6) δ ppm 10.49 (s, 1H), 10.14 (s, 1H), 8.14-8.21 (m, 1H), 8.01-8.09 (m, 1H), 7.89-8.01 (m, 4H), 7.41 (d, J=8.2 Hz, 2H), 2.32 (s, 3H), 1.63-1.74 (m, 1H), 0.63-0.87 (m, 4H).

Provenance & Evidence