N-allyl-N-(2-(cyclohexylamino)-2-oxo-1-phenylethyl)-3-nitropropanamide Gulten, S, SyntheticPages, 2011, 485
POCl₃ (Acros Organics)
Et₃N (Merck)
CHCl₃
CH₂Cl₂
MgSO₄

A solution of  POCl₃ (1.00 mmol, 0.093 mL) in CHCl₃ (3.5 mL) was added dropwise to a mixture of N-allyl-N-(2-(cyclohexylamino)-2-oxo-1-phenylethyl)-3-nitropropanamide (0.670 mmol, 250 mg) and Et₃N (2.68 mmol, 0.373 mL) in CHCl₃ (3.5 mL). After 30 min Et₃N (1.33 mmol, 0.186 mL) POCl₃ (0.499 mmol, 0.0465 mL) in CHCl₃ (1.5 mL) were added and the reaction mixture was stirred for 2 h at room temperature under nitrogen atmosphere at which point water (20 mL) was added. The crude product was extracted with CH₂Cl₂ (3 x 15 mL) and dried over anhydrous MgSO₄. After evaporation of the organic solvent, the crude product was purified by flash chromatography using silica gel (eluent: ethyl acetate-hexane; 1 : 1) to obtain title compound as a white solid (168 mg, 71% yield,  mp 192-194 ^°C, R_f= 0.20   (ethyl acetate-hexane; 1 : 1). 50:50 Mixture of diastereoisomers as determined by ¹H-NMR integration.

The author thanks Çanakkale Onsekiz Mart University (BAP 2010/109) for financial support.

IR-ATR:   3255, 3086, 2936, 2922, 2853, 1660, 1640, 1557 cm^-1
1H NMR (400 MHz, DMSO-d₆): ppm = 8.27 (1H, d, NH, J= 7.77 Hz), 7.43-7.33 (3H, m, aromatic CH), 7.23-7.20 (2H, m, aromatic CH), 6.29 (0.5H, s, CH-Ar), 6.22 (0.5H, s, CH-Ar), 4.34-4.27 (1H, m), 3.87-3.83 (1H, skew dd, CH₂O), 3.81-3.77 (1H, skew t, CH₂O), 3.71 (1H, m), 3.65-3.59 (2H, m), 3.57-3.51 (2H, m), 1.80-1.67 (4H, m, cyclohexyl CH₂), 1.57-1.54 (1H, m, cyclohexyl CH₂), 1.30-1.09 (5H, m, cyclohexyl CH₂).
¹³C NMR (100 MHz, DMSO-d₆): ppm = 167.86, 167.81, 166.38, 166.17, 155.47, 155.41, 135.92, 135.70, 128.74, 128.63, 128.60, 128.41, 127.95, 127.86, 70.31, 70.10, 59.76, 58.43, 47.72, 47.17, 46.31, 46.02, 45.84, 32.24, 32.12, 32.08, 32.06, 30.99, 25.11, 24.53, 24.44.

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