4-Cyanobenzohydrazide → 4-Cyano-benzoic acid N'-[2-(3-chloro-4-cyano-2-vinyl-phenylamino)-3-hydroxy-butyryl]-hydrazide

Participants

Reaction Conditions

Reaction Steps

2-(3-Chloro-4-cyano-2-vinyl-phenylamino)-3-hydroxy-butyric acid (690 mg, 3.8 mmol) and 4-cyanobenzohydrazide (673 mg, 4.18 mmol) were mixed together in THF (100 ml) and cooled to −15° C., under N2 atmosphere. To the pre-cooled reaction mixture were added hydroxybenzotriazole (HOBT) (514 mg, 3.8 mmol), TEA (0.8 mL, 5.7 mmol) followed by N-(3-Dimethylaminopropyl)-N′-ethylcarbodiimide hydrochloride (EDCI) (1.09 g, 5.7 mmol). The reaction mixture was allowed to stir at −20° C. for 20 min and then at room temperature overnight. After the reaction was complete based on TLC, the urea was filtered off and the solution was washed with 5% citric acid (2×60 mL), 5% NaHCO3 (2×60 mL) followed by water (60 mL) and then dried (Na2SO4) to provide the crude product as a yellow solid (0.79 g, 49%): 1H NMR (400 MHz, d6-acetone, δ in ppm) 9.92 (br s, 1H), 9.49 (br s, 1H), 7.99 (d, J=9 Hz, 2H), 7.81 (d, J=9 Hz, 2H), 7.42 (d, J=9 Hz, 1H), 6.61 (d, J=9 Hz, 1H), 6.53 (dd, J=12 and 18 Hz), 5.99 (d, J=9 Hz, 1H), 5.73 (dd, J=2 and 12 Hz, 2H), 5.64 (dd, J=2 and 18 Hz), 4.29-4.22 (m, 1H), 4.01-3.99 (m, 1H) and 1.20 (d, J=7 Hz, 3H).

Provenance & Evidence