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HETEROCYCLES, Vol. 81, No. 10, 2010
precipitated product was filtered off, washed with EtOH and dried. Recrystallization from dioxane/ EtOH
o
gave compound 5 in 80% yield, mp. 228-229 oC [lit.,25 mp. 228-230 C]; IR (KBr) v 3244 (NH), 1674
(C=O), 1655 (C=O) cm-1; 1H NMR (DMSO-d6) δ 2.12 (s, 3H, CH3), 2.53 (s, 3H, CH3), 7.15-8.70 (m, 9H,
ArH), 11.06 (s, 1H, D2O-exchangeable NH); 13C NMR (DMSO-d6) δ 18.96, 30.54, 114.69, 119.88,
120.68, 122.94, 123.74, 124.80, 138.17, 139.51, 143.22, 147.99, 149.90, 151.20, 151.96, 154.29, 160.74,
165.15, 195.42; MS m/z (%) 349 (1.61), 348 (M+, 5.48), 347 (1.19), 255 (30.06), 227 (100), 155 (10.17),
121 (6.95), 92 (2.04), 78(74). Anal. Calcd for C19H16N4O3: C, 65.51; H, 4.63; N, 16.08. Found: C, 65.59;
H, 4.69; N, 16.15%.
Method B: A mixture of butanamide 1 (1.78 g, 10 mmol) and DMF-DMA (4.0 mL, 30 mmol) was heated
on a water bath for 1 h, then left to cool. The yellow precipitated product was filtered off, washed with
EtOH and dried. Recrystallization from dioxane/ EtOH gave yellow compound identical in all respects to
compound 5.
Method C: A mixture of butanamide 1 (1.78 g, 10 mmol) and DMF-DMA (1.33 mL, 10 mmol) in DMF (5
mL) was heated on a water bath for 1 h, then left to cool. The yellow precipitated product was filtered off,
washed with EtOH and dried. Recrystallization from dioxane/ EtOH gave compound identical in all
respects to compound 5.
3-Oxo-N-(pyrid-2-yl)-2-(2-(4-sulfamoylphenyl)hydrazono)butanamide (7).
To a cold solution of the butanamide 1 (0.36 g, 2 mmol) in EtOH (50 mL), buffered with sodium acetate
trihydrate (3 g), was added the diazonium chloride
6
[prepared by diazotizing
4-aminobenzenesulfonamide (0.34 g, 2 mmol) in hydrochloric acid (6M, 1.2 mL) with sodium nitrite
solution (0.14 g, 2 mmol) in water (0.5 mL)]. The addition was carried out portionwise with stirring at 0-5
ºC over a period of 30 min. After complete addition, the reaction mixture was stirred for further 4 h, then
kept in an ice chest for 12 h, and finally diluted with water. The precipitated solid was collected by
filtration, washed with water, dried and finally recrystallized from EtOH to afford hydrazone 7 in 82%
o
1
yield, mp 234 C; IR (KBr) v 3337(NH), 3186-3200 (NH2), 1666 (C=O) cm-1; H NMR (DMSO-d6) δ
2.49 (s, 3H), 7.17-7.20 (m, 2H), 7.34 (s, 2H, D2O-exchangeable NH2), 7.67 (d, 2H), 7.84 (d, 2H), 8.15 (d,
1H), 8.38 (m, 1H), 11.54 (s, 1H, D2O-exchangeable NH), 13.78 (s, 1H, D2O-exchangeable NH); 13C
NMR (DMSO-d6) δ 22.49, 114.20, 119.34, 120.87, 127.20, 130.15, 138.07, 138.23, 139.34, 147.33,
151.16, 161.19, 197.75; MS m/z (%) 361 (M+, 15.1), 318 (74.2), 240 (19.4), 176 (14.5), 139 (33.3), 121
(30.6), 120 (10.2), 107 (31.7), 93 (27.4), 92 (7.5), 78 (100), 64 (75.3). Anal. Calcd for C15H15N5O4S: C,
49.85; H, 4.18; N, 19.38. Found: C, 49.78; H, 4.10; N, 19.30%.
5-Cyano-6-imino-4-methyl-N-(pyridin-2-yl)-1-(4-sulfamoylphenyl)-1,6-dihydropyridazine-3-carbox-
amide (8).