4-(4-Fluorophenyl)-2-oxo-2H-chromene-7-carbaldehyde → 7-({[5-(1-Ethyl-1-hydroxypropyl)-1,3,4-oxadiazol-2-yl]amino}methyl)-4-(4-fluorophenyl)-2H-chromen-2-one

Participants

Reaction Steps

A mixture of 3-(5-amino-1,3,4-oxadiazol-2-yl)pentan-3-ol (0.446 g, 2.6 mmol) and 4-(4-fluorophenyl)-2-oxo-2H-chromene-7-carbaldehyde (0.350 g, 1.3 mmol) in 5 mL of toluene was refluxed with a Dean-Stark trap overnight. After cooling to rt the solvent was removed and the crude imine diluted in ethanol (8 ml) at 0° C. Solid NaBH4 (49 mg) was added to the solution and after 30 min of stirring aqueous NH4Cl was added to destroy the excess hydride. After dilution with EtOAc-brine, the organic phase was dried with MgSO4. Purification on silica gel with toluene-EtOAc (2:8) gave the title compound. 1H NMR (400 MHz, acetone-d6): δ 7.67 (m, 2H), 7.48 (m, 2H), 7.37 (m, 3H), 7.19 (bt, 1H), 6.33 (s, 1H), 4.66 (m, 2H), 4.31 (s, 1H), 1.85 (m, 4H), 0.85 (t, 6H).

Provenance & Evidence