3-Oxo-N-[4-[4-(-3oxobutanoylamino) phenoxy]phenyl]butanamide Gulten,  Gulten, S, SyntheticPages, 2011, 499
Benzaldehyde (Acros Organics)
Thiourea (Acros Organics)
37% HCl (Merck)

A mixture of 3-oxo-N-[4-[4-(-3oxobutanoylamino) phenoxy]phenyl]butanamide (300 mg, 0.814 mmol), thiourea (185 mg, 2.44 mmol), benzaldehyde (0.25 mL, 2.44 mmol) and catalytic amoun of conc. HCl (4 drops) in EtOH (10 mL) was refluxed overnight. After the completion of reaction, the reaction mixture was allowed to cool. The solid product formed was filtered, washed with water (5 mL) and cold ether (3x5 mL) to remove the unreacted thiourea or benzaldehyde or 3-oxo-N-[4-[4-(-3oxobutanoylamino) phenoxy]phenyl]butanamide and dried. The title compound was obtained as a light yellow solid (486 mg, 94% yield).

IR-ATR:  3380, 3190,  2973, 2873, 1669, 1646, 1602, 1495, 1178, 828 cm^-1.
¹H NMR (400 MHz, DMSO-d₆): ppm = 2.07 (s, 6H, CH₃), 5.40 (s, 2H, CH) 6.90 (d, 4H, J= 8.9 Hz,  CH_Ar), 7.25-7.38 (m, 10H, CH_Ar), 7.5 (d, 4H, J= 8.9 Hz, CH_Ar), 9.42 (s, 2H, NH), 9.73 (s, 2H, NH), 9.98 (s, 2H, NH).
¹³C NMR (100 MHz, DMSO-d₆): ppm = 174.63, 165.22, 153.10, 143.53, 135.81, 134.91, 129.09, 128.16, 126.83, 121.79, 119.01, 107.70,  55.57, 16.96.

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