1,2-Dichloroethane → N'-((2R,3s)-2-(7-cyanobenzo[b]thiophen-4-ylamino)-3-hydroxybutanoyl)-4-fluorobenzohydrazide

Participants

Reaction Conditions

Reaction Steps

To a mixture of (2R,3S)-2-(7-cyanobenzo[b]thiophen-4-ylamino)-3-hydroxybutanoic acid (intermediate 60a) (0.52 g, 1.88 mmol), 4-fluorobenzoic hydrazide (295 mg, 1.91 mmol), HOBt (259 mg, 1.92 mmol) in THF:DMF (1:1) (30 mL) was added EDC (550 mg, 2.87 mmol) and Et3N (0.40 mL, 2.87 mmol) at 0° C. The mixture was stirred at 0° C. for 30 min., then at room temperature overnight. The reaction was quenched by adding water and extracted with EtOAc. The EtOAc extracts were washed with water, brine and dried over Na2SO4. Removal of the solvent and purification of the residue gave the title compound N′-((2R,3S)-2-(7-cyanobenzo[b]thiophen-4-ylamino)-3-hydroxybutanoyl)-4-fluorobenzohydrazide (0.55 g, 71%). 1H NMR (400 MHz, Acetone-d6, δ in ppm) 8.02 (dd, J=5.7, 8.6 Hz, 2H), 7.82 (d, J=5.5 Hz, 1H), 7.74 (d, J=5.5 Hz, 1H), 7.68 (d, J=8.0 Hz, 1H), 7.27 (t, J=8.6 Hz, 2H), 6.66 (d, J=8.0 Hz, 1H), 6.20 (d, J=7.2 Hz, 1H), 4.41 (m, 1H), 4.22 (dd, J=3.6, 7.2 Hz, 1H), 1.39 (d, J=6.4 Hz, 3H).

Provenance & Evidence