Hydrochloric Acid → N-cyclohexyl-N'-[3-[4-nitro-3-[(2,4-dioxoimidazolidin-5-ylidene)-methyl]phenoxy] propyl]urea

Participants

Reaction Steps

Sodium (0.50 g, 20 mg atom) was dissolved in absolute EtOH (100 mL), diethyl 2,4-dioxoimidazolidine-5-phosphonate (4.70 g, 20 mmol) added and the mixture stirred at room temperature for about 15 minutes. N-Cyclohexyl-N'-[3-(3-formyl-4-nitrophenoxy)propyl]urea (5.33 g, 15 mmol) in EtOH (75 mL) was added and the mixture stirred for about 1 hour. The solution was acidifed with 2N HCl solution, concentrated to ca. 75 mL and diluted with water. After stirring overnight, a pale yellow solid was filtered off and dried in air to give N-cyclohexyl-N'-[3-[4-nitro-3-[(2,4-dioxoimidazolidin-5-ylidene)-methyl]phenoxy] propyl]urea (6.50 g, 99 %). A 1.00 g sample was recrystallized from aqueous acetonitrile to give 0.79 g as a 5:1 (Z) to (E) mixture, mp 132°-138° C. IR (KBr) 1760, 1725, 1650, 1570, 1500, 1375, 1340, 1290, 1250 cm-1 ; 1 H NMR (DMSO-d6) δ 1.00 to 2.00 (10H, m, CH2 of cyclohexyl ring), 3.30 (2H, quintet, J=6 Hz, CO.NH.CH2), 3.35 (1H, m, N-CH), 4.11 (0.32H, t, J=6Hz, OCH2 of (Z) isomer), 4.20 (1.67H, t, J=6 Hz, OCH2 of (E) isomer), 6.62 (0.16H, s, olefinic H of (Z) isomer), 6.74 (0.84H, s, olefinic H of (E) isomer), 7.05 to 7.20 (2H, m, aryl H), 8.15 (1H, 2×d, aryl H ortho to NO2); MS m/Z 432 (MH+).

Provenance & Evidence