N-(2-(cyclohexylamino)-2-oxo-1-phenylethyl)-3-nitro-N-(prop-2-ynyl)propanamide Gulten, S, SyntheticPages, 2011, 484

POCl₃ (Acros Organics)
Et₃N (Merck)
CHCl₃
CH₂Cl₂
MgSO₄

A solution of  POCl₃ (1.01 mmol, 0.094 mL) in CHCl₃ (3.5 mL) was added dropwise to a mixture of N-(2-(cyclohexylamino)-2-oxo-1-phenylethyl)-3-nitro-N-(prop-2-ynyl)propanamide (0.674 mmol, 250 mg) and Et₃N (2.70 mmol, 0.376 mL) in CHCl₃ (3.5 mL). After 30 min Et₃N (1.35 mmol, 0.188 mL) POCl₃ (0.505 mmol, 0.047 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 (3x15 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 cream color solid (171 mg, 72% yield,  mp 201-204 ^°C, R_f= 0.32   (ethyl acetate-hexane; 1 : 1).

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

IR-ATR:  3252, 3085, 2936, 2852, 1658, 1644, 1631, 1562 cm^-1
1H NMR (400 MHz, DMSO-d₆):  ppm = 8.69 (1H, s, isoxazole CH ), 8.29 (2H, d, NH, J= 7.72 Hz), 7.43-7.35 (3H, m, aromatic CH), 7.25-7.23 (2H, d, aromatic CH, J= 7.16 Hz), 6.32 (1H, s, CH-Ar), 4.68 (1H, d, CH₂NCO, J= 15.42 Hz), 3.85 (1H, d, CH₂NCO, J= 15.03 Hz), 3.82 (s, 2H, CH₂O), 3.65-3.58 (1H, m, CHNH ), 1.80-1.64 (4H, m, cyclohexyl CH₂), 1.56-1.53 (1H, m, cyclohexyl CH₂), 1.28-1.06 (5H, m, cyclohexyl CH₂).
¹³C NMR (100 MHz, DMSO-d₆): ppm = 167.90, 166.18, 156.76, 153.72, 135.58, 128.73, 128.04, 127.84, 110.52, 59.18, 47.72, 32.21, 32.12, 29.68, 25.10, 24.53, 24.44.

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