158
S. Bondock et al.
yield 71%; mp 255–256ꢁC; IR (KBr): ꢂꢀ¼ 3250–3160 (2NH),
134 (14.7), 105 (100), 81 (14.8), 78 (26.7), 77 (61.8), 53
(24.8), 51 (17.6).
1
2210 (CꢃN), 1665, 1647 (2C¼O), 1592 (C¼N) cmꢂ1; H
NMR (DMSO-d6): ꢁ ¼ 3.98 (s, OCH3), 6.12 (s, thiazole C5-
H), 7.26–7.90 (m, 5Ar–H), 7.95, 8.06 (two d, J ¼ 8.0 Hz,
each 2H, 4Ar–H), 8.60 (s, NH), 10.20 (s, br, NH) ppm; MS
(EI, 70 eV): m=z (%) ¼ 496 (Mþ, 20.6), 419 (7.1), 319
(10.6), 374 (12.9), 365 (22.6), 322 (16.6), 294 (27.1), 175
(14.3), 163 (41.7), 122 (7.5), 107 (5.4), 105 (100), 77 (62.9),
51 (28.5).
2-(4-Benzoyl-5-ethylsulfanyl-4H-1,2,4-triazol-3-yl)-
acetonitrile (13, C13H12N4OS)
To a cold suspension of 1.38 g anhydrous K2CO3 (1mmol) in
30cm3 DMF, 2.62 g 1 (1mmol) were added, followed by ad-
dition of 1.55 g ethyl iodide (1mmol). The mixture was stirred
at room temperature for 24h. The reaction mixture was then
triturated with 50cm3 cold water, and acidified with dilute
HCl. The resultant solid product, so precipitated, was collect-
ed by filtration, dried well, and crystallized from ethanol
to give compound 13. Yellow crystals; yield 65%; mp 232–
8-(4-Methoxyphenylazo)-2-phenyl-4-thioxo-3,4-dihydropy-
razolo[1,5-a][1,3,5]triazin-7(6H)-one (8, C18H14N6O2S)
A solution of 1.98 g 2 (5 mmol) in 15 cm3 ethanol was treat-
ed with 20 cm3 aqueous 5% potassium hydroxide, then
refluxed for 2 h, left to cool, diluted with water, and acidified
with dilute HCl. The solid product formed was collected
by filtration, dried well, and crystallized from a mixture of
EtOH-CHCl3 (1:1) to give compound 8. Brown crys-
tals; yield 72%; mp 277–278ꢁC; IR (KBr): ꢂꢀ¼ 3300–
1
233ꢁC; IR (KBr): ꢂꢀ¼ 2245 (CꢃN), 1682 (C¼O) cmꢂ1; H
NMR (DMSO-d6): ꢁ ¼ 1.16 (t, J ¼ 7.5 Hz, CH3), 3.03 (q,
J ¼ 7.5 Hz, SCH2), 4.69 (s, NCCH2), 7.41–7.94 (m, 5Ar–H)
ppm; MS (EI, 70eV): m=z (%) ¼ 272 (Mþ, 16.0), 211 (31.5),
167 (23.9), 138 (34.8), 105 (100), 77 (38.9), 51 (15.6).
3100 (2NH), 1645 (C¼O), 1582 (N¼N) cmꢂ1
;
1H NMR
N-(4-(2-Cyanoacetyl)-5-oxo-5,6-dihydro-4H-1,3,4-
(DMSO-d6): ꢁ ¼ 3.95 (s, OCH3), 7.26–7.88 (m, 5Ar–H),
8.05, 8.26 (two d, J ¼ 7.8 Hz, 4Ar–H), 8.35 (s, br, NH),
9.28 (s, br, NH) ppm; MS (EI, 70 eV): m=z (%) ¼ 378
(Mþ, 9.1), 350 (14.3), 243 (20.3), 148 (30.9), 118 (100),
77 (35.1), 51 (13.9).
thiadiazin-2-yl)benzamide (16, C13H10N4O3S)
To a cold suspension of 1.38 g anhydrous K2CO3 (1mmol) in
30cm3 DMF, 2.62 g 1 (1mmol) were added, followed by
addition of 1.65 g ethyl bromoacetate (1mmol). The mixture
was stirred at room temperature for 20h. The reaction mixture
was then triturated with 50cm3 cold water, and few drops of
dilute HCl were added till pH¼ 7. The resultant solid product,
so precipitated, was collected by filtration, dried well, and
crystallized from ethanol to give compound 16. Orange crys-
tals; yield 61%; mp 255–256ꢁC; IR (KBr): ꢂꢀ¼ 3234 (NH),
Synthesis of Bisheterocyclic Compounds 12a–12b
A mixture of 2.62g 1 (1mmol) and the appropriate ꢀ-halo-
ketone (bromoacetone or phenacyl bromide) (2mmol) in
30cm3 absolute ethanol containing 2 g freshly fused sodium
acetate (25 mmol) was refluxed for 6 h, then allowed to cool.
The precipitate that formed was filtered off, washed with
water, dried, and recrystallized from ethanol to give the bishet-
erocyclic compounds 12a–12b.
2232 (CꢃN), 1672, 1660, 1645 (3C¼O) cmꢂ1
;
1H NMR
(DMSO-d6): ꢁ ¼ 4.29 (s, thiadiazine ring CH2), 4.65 (s,
NCCH2), 7.51–7.94 (m, 5Ar–H), 11.14 (s, NH) ppm; MS
(EI, 70eV): m=z (%) ¼ 302 (Mþ, 32.2), 262 (16.9), 170 (23.0),
154 (49.6), 105 (100), 77 (71.7), 51 (16.8).
N-(3-(3-Cyano-5-methyl-2-oxo-2,3-dihydro-1H-pyrrol-
1-yl)-4-methylthiazol-2(3H)-ylidene)benzamide
(12a, C17H14N4O2S)
2-(2-Benzamido-6-(2-(4-methoxyphenyl)-hydrazono)-5-oxo-
5,6-dihydro-4H-1,3,4-thiadiazin-4-yl)-N0-(4-methoxyphenyl)-
2-oxoacetohydrazonoyl cyanide (17, C25H18N8O3S)
Brown crystals; yield 68%; mp 272–273ꢁC; IR (KBr): ꢂꢀ¼
2235 (CꢃN), 1665 (C¼O), 1645 (ring C¼O), 1592 (C¼N)
cmꢂ1; 1H NMR (DMSO-d6): ꢁ ¼ 2.08 (s, CH3), 2.21 (s, CH3),
4.49 (d, J ¼ 2.5 Hz, pyrrole C3-H), 5.56 (d, J ¼ 2.5 Hz, pyrrole
C4-H), 6.23 (s, thiazole C5-H), 7.47–7.94 (m, 5Ar–H) ppm;
MS (EI, 70 eV): m=z (%) ¼ 338 (Mþ, 9.8), 233 (6.5), 218
(15.2), 190 (19.6), 163 (8.2), 121 (4.3), 105 (100), 77 (43.5),
51 (16.9).
A well stirred solution of 0.62 g p-anisidine (5mmol) in
1.5 cm3 concentrated HCl and 3 cm3 H2O was cooled in an
ice-bath at 0–5ꢁC and diazotized with the solution of 0.35 g
NaNO2 in 5 cm3 H2O. Then, the above cold diazonium solu-
tion was added dropwise to a well stirred cold solution of
0.75g 16 (25 mmol) in 25 cm3 pyridine. The reaction mixture
was stirred for 2 h until complete coupling reaction was
reached. The solid product obtained, was filtered off, washed
with cold water, and recrystallized from a mixture of EtOH–
DMF (1:1) to give compound 17. Red crystals; yield 82%; mp
283–284ꢁC; IR (KBr): ꢂꢀ¼ 3325–3185 (3 NH), 2212 (CꢃN),
N-(3-(3-Cyano-2-oxo-5-phenyl-2,3-dihydro-1H-pyrrol-
1-yl)-4-phenylthiazol-2(3H)-ylidene)benzamide
(12b, C27H18N4O2S)
Green crystals; yield 74%; mp 287–288ꢁC; IR (KBr): ꢂꢀ¼
1664, 1652, 1643 (3C¼O), 1625 (C¼N) cmꢂ1
;
1H NMR
2237 (CꢃN), 1665 (C¼O), 1647 (ring C¼O), 1596 (C¼N)
(DMSO-d6): ꢁ ¼ 3.88 (s, OCH3), 3.95 (s, OCH3), 7.28–7.81
(m, 5Ar–H), 7.85, 7.94 (two d, J ¼ 7.9 Hz, 4Ar–H), 8.15, 8.25
(two d, J ¼ 8.0 Hz, 4Ar–H), 9.74 (s, br, 2NH), 10.87 (s, br,
NH) ppm; MS (EI, 70eV): m=z (%) ¼ 570 (Mþ, 13.7), 406
(8.6), 284 (14.6), 174 (16.6), 122 (25.7), 105 (100), 77 (61.1),
51 (16.9).
1
cmꢂ1; H NMR (DMSO-d6): ꢁ ¼ 4.64 (d, J ¼ 2.6 Hz, pyrrole
C3-H), 5.67 (d, J ¼ 2.6 Hz, pyrrole C4-H), 6.66 (s, thiazole
C5-H), 7.26–7.99 (m, 15Ar–H) ppm; MS (EI, 70 eV): m=z
(%) ¼ 462 (Mþ, 9.8), 357 (Mþ-PhCO, 19.9), 299 (24.6), 279
(3.3), 271 (12.8), 245 (23.5), 183 (15.7), 163 (7.4), 155 (19.4),