[O-:1][CH2:2][CH3:3].[Na+].[Na].C([O:9][C:10](=O)[CH2:11][CH2:12][CH2:13][CH3:14])(=O)C.C(O[CH:19]=[C:20]([C:23]#[N:24])[C:21]#[N:22])C.Cl.C([OH:28])C>>[CH2:2]([O:1][C:10](=[O:9])[C:11]1[CH:19]=[C:20]([C:21]#[N:22])[C:23]([NH2:24])=[C:13]([CH3:14])[C:12]=1[OH:28])[CH3:3]To a solution of sodium ethoxide (1.3 L) (freshly prepared by addition of sodium metal (7.9 g, 0.35 mol) to ethanol (1.3 L)) at 0° C. was added ethylpropionyl acetate (25 g, 0.17 mol) and the solution was stirred at RT for 1 h. To the above solution was added ethoxymethylene malononitrile (21 g, 0.17 mol) at RT and the reaction mixture was refluxed at 80° C. for 2 h. The reaction mixture was cooled, neutralized to pH=7 by addition of 1.5 N HCl and concentrated under vacuum. The obtained residue was diluted with water (100 mL) and filtered. The solid was washed with water and dried under vacuum at 50° C. to give the crude product (27 g). The crude solid was washed with 5% ethyl acetate in pet. ether which gave pure title compound (22.5 g, 59%).
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