Hydrazine → 6-fluoro-3-iodo-1-tosyl-1H-indole-5-carbohydrazide

Participants

Reaction Steps

HOBt (Aldrich, St. Louis, Mo., 303 mg, 2.24 mmol), EDC HCl (430 mg, 2.242 mmol) and 6-fluoro-3-iodo-1-tosyl-1H-indole-5-carboxylic acid (858 mg, 1.87 mmol) were weighed into a 250 mL round bottomed flask and treated with DMF (7 mL). The resulting solution was stirred at RT for 30 min. The reaction mixture was then treated with anhydrous hydrazine (0.29 mL, 9.34 mmol) and stirred at RT for 30 min. The reaction mixture was diluted with water resulting in precipitate formation. The solid was collected by filtration, washed with water, and dried under high vacuum for 3 h at 50° C., affording crude 6-fluoro-3-iodo-1-tosyl-1H-indole-5-carbohydrazide (2.17 g) as a light yellow amorphous solid. MS (ESI, pos. ion) m/z: 473.9 (M+H)+. 1H NMR (400 MHz, DMSO-d6) δ ppm 9.59 (1H, br. s.), 8.17 (1H, s), 8.01 (2H, d, J=8.4 Hz), 7.97 (5H, s), 7.82 (1H, d, J=10.8 Hz), 7.50 (1H, d, J=6.5 Hz), 7.45 (3H, d, J=8.2 Hz), 4.56 (2H, br. s.), 4.11 (3H, br. s.), 2.36 (4H, s).

Provenance & Evidence