Synthesis of N-Arylsulfonylaminated Biheterocycles
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N-Arylsulfonylamino-2-pyridones (6a–h)
Method A. A mixture of compounds 2a,b (0.01 mmol) and -(2-
furanyl)- or -(2-thienyl)acrylonitrile derivatives 3a–d (0.01 mmol) in
ethanol (30 ml) containing a few drops of piperidine is refluxed for 3 h.
The resulting product precipitates from the hot solution is collected by
filtration and then recrystallized from the appropriate solvent.
Method B. To a mixture of 8 (0.01 mmol) and an arenesulfonyl chlo-
ride (0.01 mmol) in ethanol (50 ml) was added piperidine (0.05 ml). The
reaction mixture was stirred at room temperature until the reaction
was complete (TLC) and then set aside overnight. The resultant pre-
cipitate was filtered off and crystallized from the appropriate solvent.
6a: reddish brown, m.p. 302–304 C (from EtOH) yield (94%); IR (KBr
disc) max/cm 1 3320, 3280 (NH, NH2), 2214 (CN), 1690 (CO); 1H NMR
(DMSO) ; 7.15–7.90 (m, 8H, furan H-3,4,5 and C6H5), 8.90 (s, br, 2H,
NH2), 11.50 (s, br, 1H, NH); C17H11N5O4S (381), Calcd: C, 53.54; H,
2.88; N, 18.37. Found: C, 53.1; H, 2.1; N, 18.3%.
6b: red, m.p. > 300 C (from EtOH) yield (86%); IR (KBr disc)
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max/cm 3320, 3300 (NH, NH2); 2220 (CN), 1670 (CO); 1H NMR
(DMSO) , 2.51 (s, 3H, CH3), 7.25–7.94 (m, 7H, furan H-3,4,5 and C6H4),
8.50 (s, br, 2H, NH2), 11.80 (s, br, 1H, NH); C18H13N5O4S (395), Calcd:
C, 54.68; H, 3.29; N, 17.70. Found: C, 55.0; H, 3.3; N, 17.5%.
6c: white, m.p. 240–242 C (from EtOH) yield (90%); IR (KBr disc)
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max/cm 3380, 3271 (NH, NH2); 2259 (CN), 1680 (CO); 1H NMR
(DMSO) , 7.00–7.70 (m, 8H, thiophene H-3,4,5 and C6H5), 7.78 (s, br,
2H, NH2), 11.77 (s, br, 1H, NH); C17H11N5O3S2 (397) (M+ = 397), Calcd:
C, 51.38; H, 2.77; N, 17.63. Found: C, 51.1; H, 3.0; N, 17.9%.
6d: white, m.p. 158–160 C (from EtOH) yield (95%); IR (KBr disc)
max/cm 1 3450, 3390, 3197 (NH, NH2), 2214 (CN), 1690 (CO); 1H NMR
(DMSO) , 2.68 (s, 3H, CH3), 7.18 (s, br, 2H, NH2), 7.73–8.21 (m, 7H,
thiophene H-3,4,5 and C6H4), 11.65 (s, br, 1H, NH), C18H13N5O3S2
(411), Calcd: C, 52.55; H, 3.16; N, 17.93. Found: C, 53.0; H, 2.9; N, 16.8%.
6e: reddish brown, m.p. > 300 C (from EtOH) yield (85%); IR (KBr
1
disc) max/cm 3350, 3190 (NH2), 1720 (CO), 1632 (CO); 1H NMR
(DMSO) , 0.99 (t, 3H, CH3), 3.90 (q, 2H, CH2), 7.12–7.88 (m, 8H, fu-
ran H-3,4,5 C6H5), 8.56 (s, br, 2H, NH2), 10.3 (s, 1H, NH); C19H16N4O6S
(428), Calcd: C, 53.27; H, 3.73; N, 13.08. Found: C, 52.9; H, 3.9; N, 13.9%.
6f: reddish brown, m.p. > 300 C (from EtOH) yield (95%); IR (KBr
1
disc) max/cm 3307 (NH, NH2), 2225 (CN), 1737 (CO), 1680 (CO);
1H NMR (DMSO) , 0.75 (t, 3H, CH3), 2.42 (s, 3H, CH3), 3.72 (q, 2H,
CH2), 7.25–7.8 (m, 7H, furan H-3,4,5 C6H4), 8.18 (s, br, 2H, NH2), 9.20
(s, 1H, NH); C20H18N4O6S (442), Calcd: C, 54.29; H, 4.07; N, 12.66.
Found: C, 54.4; H, 3.8; N, 13.0%.