[C:1]1([NH:7][NH2:8])[CH:6]=[CH:5][CH:4]=[CH:3][CH:2]=1.C([O-])([O-])=O.[K+].[K+].[CH2:15]([O:17][C:18]([C:20]#[C:21][C:22](OCC)=[O:23])=[O:19])[CH3:16].Cl>C(O)C.O>[OH:23][C:22]1[N:7]([C:1]2[CH:6]=[CH:5][CH:4]=[CH:3][CH:2]=2)[N:8]=[C:20]([C:18]([O:17][CH2:15][CH3:16])=[O:19])[CH:21]=1To a solution of phenyl hydrazine (10 g, 92.6 mmol) in absolute ethanol (100 mL) is added dry K2CO3 (15.3 g, 111 mmol) and followed by slow addition of diethylacetylene dicarboxylate (10.6 g, 62.03 mmol) and the reaction mixture is heated at 85° C. for 12 h. The reaction mixture is then cooled to rt and 38 mL of 6N HCl is added dropwise. The reaction mixture is diluted with 150 mL water, extracted with ethylacetate. The organic layer is washed with water twice, dried over Na2SO4 and concentrated under vacuum. The residue is triturated with MTBE and the solid formed is filtered, washed with MTBE and dried to afford the title compound. 1H NMR (DMSO-d6, 400 MHz): δ 12.12 (bs, 1H), 7.72-7.70 (m, 2H), 7.51-7.47 (m, 2H), 7.37-7.34 (m, 1H), 5.93 (s, 1H), 4.26 (q, J=4.1 Hz, 2H), 1.27 (t, J=7.1 Hz, 3H). MS (ESI+): 233.2.
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