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

Participants

Reaction Conditions

Reaction Steps

To a mixture of (2R,3R)-2-(7-cyanobenzo[b]thiophen-4-ylamino)-3-hydroxybutanoic acid (intermediate 61a) (0.62 g, 2.24 mmol), benzoic hydrazide (310 mg, 2.28 mmol), HOBt (308 mg, 2.28 mmol) in THF:DMF (1:1) (30 mL) was added EDC (645 mg, 3.36 mmol) and Et3N (0.47 mL, 3.37 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. After concentration, the residue was purified by flash chromatography to give two fractions. The first fraction (208 mg) contained mainly the title compound and some impurities. The second fraction was the pure desired compound N′-((2R,3R)-2-(7-cyanobenzo[b]thiophen-4-ylamino)-3-hydroxybutanoyl)benzohydrazide (0.58 g, 66%). 1H NMR (400 MHz, Acetone-d6, δ in ppm) 7.95 (m, 2H), 7.84 (d, J=5.7 Hz, 1H), 7.71 (d, J=5.7 Hz, 1H), 7.67 (d, J=8.2 Hz, 1H), 7.60 (m, 1H), 7.50 (m, 2H), 6.69 (d, J=8.2 Hz, 1H), 6.37 (d, J=6.9 Hz, 1H), 4.18˜4.26 (m, 2H), 1.41 (d, J=6.3 Hz, 3H).

Provenance & Evidence