[CH3:1][C:2]([CH3:16])=[CH:3][CH2:4][NH:5][C:6]([C:8]1[O:9][C:10]([N+:13]([O-:15])=[O:14])=[CH:11][CH:12]=1)=[O:7].[ClH:17].[N:18]([O:20]CCC(C)C)=O>>[Cl:17][C:2]([CH3:16])([CH3:1])[CH:3]([N:18]=[O:20])[CH2:4][NH:5][C:6]([C:8]1[O:9][C:10]([N+:13]([O-:15])=[O:14])=[CH:11][CH:12]=1)=[O:7]N-(3-Methyl-2-butenyl)-5-nitro-2-furancarboxamide (2.2 g, 0.01 mol) was suspended in isoamyl nitrite (60 mL) and cooled to -5° C. Concentrated HCl (1 mL, 37%, 0.01 mol) was added through a syringe. The reaction mixture was stirred at -5° C. for 30 min and at room temperature for 30 min. The solid was filtered and washed with chilled (-10° C.) ethanol-ether [100 mL). A light green powder was obtained. Yield: 1.5 g (52%). mp 110°-112° C. MS m 254 [(M+H)-HCl]+. 1H NMR (DMSO-d6) δ1.82 [s, 6H, (C H3)2C=], 4.28 (d, 2H, C H2C=N), 7.49 and 7.75 (d, 2H, furanyl-H), 8.66 (t, 1H, N HCO), 11.72 (s, 1H, C=NO H).
불러오는 중…