[CH2:1]([C:3]1[O:7][N:6]=[C:5]([C:8]2[CH:13]=[CH:12][CH:11]=[CH:10][CH:9]=2)[C:4]=1[C:14]([OH:16])=O)[CH3:2].Cl.[Cl:18][CH2:19][CH2:20][CH2:21][NH2:22].C(N(CC)CC)C.O>CN(C)C=O>[Cl:18][CH2:19][CH2:20][CH2:21][NH:22][C:14]([C:4]1[C:5]([C:8]2[CH:9]=[CH:10][CH:11]=[CH:12][CH:13]=2)=[N:6][O:7][C:3]=1[CH2:1][CH3:2])=[O:16]A solution of 3.1 g of 5-ethyl-3-phenylisoxazole-4-carboxylic acid (prepared as described in J. Org. Chem. 1985, 50, 5660-5666), 2.94 g of 3-chloropropylamine hydrochloride, 2.62 mL of 92% diethyl cianoposphonate and 4.38 mL of triethylamine in 50 mL of anhydrous dimethylformamide was stirred at room temperature for 3 hours, poured into 500 mL of water and extracted with ethyl acetate (2×200 mL). The combined organic layers were washed with water, dried (sodium sulphate) and the solvent was evaporated under vacuum. The crude was purified by flash chromatography (ethyl acetate-petroleum ether 3:7) to give 3.35 g (73%) of the title compound. M.p. 75-76° C.
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