27 (2.85 g, 87%) as colorless crystals; mp 255-256oC (ethanol). IR spectrum, ν, cm–1: 3292 (NH), 3003 (CH
aromatic), 2924 (CH aliphatic), 1646 (C=O pyridazinone). Mass spectrum, m/z (I, %): 329 [M+] (14.44), 330
[M+1] (3.44), 287 (100), 227 (11.93), 289 (10.96), 176 (20.75) 149 (19.64), 77 (0.36). Found, %: C 72.98;
H 4.35; N 12.85. C20H15N3O2. Calculated, %: C 72.95; H 4.56; N 12.77.
4-(6-Methyl-1H-2-thioxopyrimidin-4-yl)-5,6-diphenylpyridazin-3(2H)-one (28). This compound was
prepared by the same method used in preparing compound 25 using thiourea instead of hydrazine hydrate. It was
crystallized from absolute ethanol (2.57 g, 69%) as yellowish crystals; mp 203-205oC. IR spectrum, ν, cm–1:
1
3191 (NH), 2994 (CH aliphatic), 1646 (C=O), 1580 (C=N), 1193 (C=S). H NMR spectrum, δ, ppm (J, Hz):
1.97 (3H, s, CH3); 5.66 (1H, s, H-5 pyrimidine); 7.12-7.30 (10H, m, H Ar); 13.64, 13.77 (2H, 2s, 2NH). Mass
spectrum, m/z (I, %): 372 [M+] (0.23), 369 [M–3] (1.82), 289 (100), 77 (7.92), 57 (15.29). Found, %: C 67.56; H
4.45; N 15.22; S 8.55. C21H16N4OS. Calculated, %: C 67.74; H 4.30; N 15.05; S 8.60.
4-(2-Imino-6-methyl-1H-pyrimidin-4-yl)-5,6-diphenylpyridazin-3(2H)-one (29). This compound
was prepared by the same method used for compound 25 using guanidine hydrochloride instead of hydrazine
hydrate. Compound 29 (2.4 g, 67%) was recrystallized from ethanol as brownish-red crystals; mp 215–216oC.
1
IR spectrum, ν, cm–1: 3422, 3298 and 3190 (NH and NH2), 2993 (CH aliphatic), 1647 (C=O), 1580 (C=N). H
NMR spectrum, δ, ppm: 1.97 (3H, s, CH3); 5.67 (1H, s, H-5 pyrimidine); 7.12–7.23 (10H, m, H Ar); 13.60,
13.77 (2H, s, 2NH pyrimidine); 13.78 (1H, s, enolic OH pyridazine). Mass spectrum, m/z (I, %): 355 [M+]
(8.45), 289 (100), 129 (13.15), 89 (22.07), 77 (24.41). Found, %: C 70.70; H 4.69; N 19.66. C21H17N5O.
Calculated, %: C 70.99; H 4.79; N 19.72.
4-[α-(3-Nitrophenylethylideneamino)-6-methyl-2-thioxopyrimidin-4-yl]-5,6-diphenylpyridazin-3(2H)-
one (31). This compound was prepared by the same method applied for compound 25 using N-1-(m-
nitrophenylethylidene)thiosemicarbazide 30 (obtained from condensation of acetophenone with thiosemi-
carbazide). Compound 31 (3.3 g, 62%) was crystallized from ethanol as colorless crystals; mp 212-213oC.
1
IR spectrum, ν, cm–1: 3370, 3219 (NH), 2996 (CH aliphatic), 1646 (C=O), 1603 (C=N), 1180 (C=S). H NMR
spectrum, δ, ppm: 1.97 (3H, s, 6-CH3 pyrimidine); 2.39 (s, 3H, CH3); 5.65 (s, 1H, H-5 pyrimidine); 7.11-7.61
(14H, m, H Ar); 10.41 (1H, s, NH). Mass spectrum, m/z (I, %): 534 [M+] (30), 310 (100), 521 (17.86), 500
(33.33), 295 (55.95), 334 (52.76), 56 (19.05). Found, %: C 65.37; H 4.32; N 15.80; S 6.00. C29H22N6O3S.
Calculated, %: C 65.17; H 4.12; N 15.73; S 5.99.
4-{6-Methyl-1-[(2-methyl-2-(3-nitrophenyl)-4-oxothiazolidin-3-yl]-2-thioxo-1,2-dihydropyrimidin-
4-yl}-5,6-diphenylpyridazin-3(2H)-one (32). A mixture of compound 31 (5.35 g, 10 mmol) and thioglycolic
acid (1.1 g, 12 mmol) in dry benzene was refluxed in water bath for 4 h. The solid obtained was collected to give
compound 32 (3.84 g, 63%) as colorless crystals; mp 218-220oC (ethanol). IR spectrum, ν, cm–1: 3369 (OH
1
enolic thiazolidinone), 3214 (NH), 2975 (CH aliphatic), 1637 (C=O), 1602 (C=N). H NMR spectrum, δ, ppm:
2.02 (3H, s, 6-CH3 pyrimidine); 2.38 (3H, s, 2-CH3, thiazolidinone); 7.06–8.62 (15H, m, H Ar and H-5
pyrimidine); 10.42 (1H, s, enolic OH thiazolidinone); 13.58 (1H, s, enolic OH pyridazine). Mass spectrum, m/z
(I, %): 608 [M+] (22.3), 388 (20.27), 333 (14.70), 238 (22.05). Found, %: C 60.90; H 4.01; N 13.67; S 10.36.
C31H24N6O4S2. Calculated, %: C 61.18; H 3.95; N 13.82; S 10.53.
4-(3-Cyano-6-methyl-2-oxo-1,2-dihydropyridin-4-yl)-5,6-diphenylpyridazin-3(2H)-one (33).
A
mixture of compound 17 (3.32 g, 10 mmol) and cyanoacetamide (1 g, 12 mmol) in absolute ethanol (20 ml)
containing a catalytic amount of triethylamine was heated under reflux for 4 h. The solid obtained upon cooling
was collected to give compound 33 (3.26 g, 83%) as yellow crystals; mp 201–203oC (ethanol). IR spectrum, ν,
cm–1: 3407 (OH enolic pyridine), 3192 (NH), 2967 (CH aliphatic), 2270 (C≡N), 1646 (C=O), 1580 (C=N) cm–1.
1H NMR spectrum, δ, ppm: 2.05 (3H, s, CH3); 5.64 (1H, s, H-3 pyridine); 7.11–7.26 (10H, m, H Ar); 7.66 (1H, s,
NH pyridine); 13.63 (1H, s, enolic OH pyridazine). Mass spectrum, m/z (I, %): 380 [M+] (0.22), 289 (100), 332
(8.08), 304 (8.51), 290 (24.71), 77 (20.01). Found, %: C 72.50; H 4.15; N 14.55. C23H16N4O2. Calculated, %:
C 72.63; H 4.21; N 14.74.
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