An efficient synthesis, X-ray and spectral characterization of biphenyl derivatives
399
(40), 165 (100), 152 (15), 139 (10), 106 (15), 91 (10), DMSO-d6)δ 3.70 (s, 2H, CH2), 4.21 (s, br, 2H, NH2),
78 (15), 63 (8), 44 (95); Anal. Calcd. For C36H27N5O2S: 4.45 (s, 2H, CH2), 7.12 (d, 2H, ArH), 7.36 (d, 2H,
C, 72.83; H, 4.58; N, 11.80%. Found: C, 72.86; H, ArH), 7.60 - 7.95 (m, 4H, ArH), 9.20 (s, 1H, NH); 13
C
4.58; N, 11.86%.
NMR (300 MHz, DMSO-d6)δ 40.0, 49.0, 127.2, 127.5,
127.6, 127.8, 127.9, 134.6, 135.1, 135.4, 148.0, 148.4,
163.0, 165.0, 169.0; IR (cm−1): νmax 3425 (br, NH2),
3350 (NH), 1746 (S-CO), 1650 (amide carbonyl), 1640
(N-CO); MS (m/z): 341 (100), 310 (67), 282 (51), 241
(74), 209 (40), 189 (60), 153 (62), 128 (92), 77 (49),
51 (37); Anal. Calcd. For C17H15N3O3S: C, 59.81; H,
4.43; N, 12.31%. Found: C, 59.84; H, 4.40; N, 12.37%.
3.3i Step 5: Deprotection of NH group: A solu-
tion of compound 14 (4.90 g, 8.42 mmol), HCl (10%,
40 mL) and THF (50 mL) was stirred at 25 ◦C for 4 h.
To the reaction mixture sodium hydroxide (10%) was
added and stirred for 30 min. The solvent was removed
in vacuo and the resulting residue was dissolved in
water and the clear filtrate was adjusted to pH 3 by dil
HCl. The precipitated product was filtered to get crude
material, which was recrystallized in acetone to get pale
yellow coloured crystals of 9.
3.4c Synthesis of 3-[{2ꢁ-(4-amino-5-sulfanyl-4H-1,2,
4-triazol-3-yl)-biphenyl-4-yl} methyl]-2,4-dioxo-1,3-
thiazolidine (16): The acid hydrazide 15 (3.41 g,
10.0 mmol) was added to absolute alcohol (50 mL),
containing KOH (1.60 g) at room temperature. Carbon
disulphide was then added (2.30 g, 13 mmol) and the
mixture was stirred at room temperature for 10 h and
was then diluted with ether (10 mL) and stirred further
for 1 h. The potassium salt thus separated was taken
in water (20 mL) and refluxed with hydrazine hydrate
(99%) (20 mmol) for 3 h. During this time hydrogen
sulphide was evolved and the colour of the reaction
mixture changed to bright yellow. It was then cooled
to 5 ◦C and acidified with conc. HCl. A yellow solid
separated out was filtered, washed with water and
crystallized from ethanol to get the triazole derivative
16.
3.3j 5-[2-{4ꢁ-(2,4-Dioxo-1,3-thiazolidin-3-yl)-methyl}-
biphenyl]-1H-tetrazole (9): 2.95 g, 87% yield. m.p.
216–218 ◦C. 1H NMR (300 MHz, DMSO-d6)δ 3.72 (s,
2H, CH2), 4.67 (s, 2H, CH2), 7.12 (d, 2H,J = 8.05 Hz,
ArH), 7.36 (d, 2H,J = 8.05 Hz, ArH), 7.45-7.62 (m,
4H, ArH); 13C NMR (300 MHz, DMSO-d6)δ 35.1,
44.2, 127.5, 127.7, 128.0, 128.2, 129.3, 135.1, 134.5,
135.4, 140.6, 163.5, 165.0, 168.0; IR (cm−1): νmax
1749, (SC=O), 1670 (NC=O), 3411 (NH); MS (m/z):
351 (32), 350 (100), 322 (20), 248 (15), 206 (60), 205
(90), 192 (25), 178 (85), 165 (45), 152 (50), 139 (25),
118 (20), 102 (20), 89 (20), 77 (25), 62 (30), 47 (25),
46 (55), 42 (11); Anal. Calcd. For C17H13N5O2S: C,
58.11; H, 3.73; N, 19.93%. Found: C, 58.05; H, 3.68;
N, 19.90%.
3.4d 3-[{2ꢁ-(4-Amino-5-sulfanyl-4H-1,2,4-triazol-3-yl)
biphenyl-4-yl}-methyl]-2,4-dioxo-1,3-thiazolidine (16):
72% yield. m.p. 128–129 ◦C. 1H NMR (300MHz,
DMSO-d6) δ 2.56 (s, 2H, NH2, D2O exchanged), 3.01
(s, 1H, SH), 3.58 (s, 2H, CH2), 4.62 (s, 2H, CH2), 7.00
(d, 2H, J = 7.10 Hz, ArH), 7.14 (d, 2H, J = 7.10 Hz,
ArH), 7.20 - 7.48 (m, 4H, ArH); 13C NMR (300 MHz,
DMSO-d6)δ 40.0, 49.0, 127.2, 127.5, 127.6, 127.8,
127.9, 129.0, 134.6, 135.1, 135.4, 141.3, 148.0, 148.4,
165.6, 169.2; IR (cm−1): νmax 3326 (NH), 2372 (SH),
1746 (S-CO), 1640 (N-CO); MS (m/z): 397 (71), 381
(100), 322 (93), 308 (43), 282 (11), 255 (50), 223 (40),
181 (22), 153 (40), 128 (60), 102 (80), 91 (60), 77 (65);
Anal. Calcd. For C18H15N5O2S2: C, 54.39; H, 3.80; N,
17.62%. Found: C, 54.42; H, 3.74; N, 17.58%.
3.4 General procedure for the formation
of the compounds 16, 17
The synthesis of the compounds 16–17 involves follow-
ing steps.
3.4a Preparation of 4ꢁ-[(2,4-dioxo-1,3-thiazolidin-3-
yl)-methyl]-biphenyl-2-carbohydrazide (15): A mix-
ture of the compound 8 (1.71 g, 5.0 mmol) and hydra-
zine hydrate (99%, 50 mmol) in ethanol (100 mL) was
refluxed for 3 h. The solution on cooling gave a solid
mass of acid hydrazide 15 which was collected by filtra-
tion and recrystallized from ethanol (1.09 g, 64% yield.
m.p. 180–181 ◦C) and used for the synthesis of final
products 16 and 17–18.
3.4e Synthesis of 3-[{2ꢁ-(5-phenyl-1,3,4-oxadiazol-2-
yl)-biphenyl-4-yl}-methyl]-2,4-dioxo-1,3-thiazolidine
3.4b 4ꢁ-[(2,4-Dioxo-1,3-thiazolidin-3-yl)-methyl]-bi- (17): A mixture of benzoic acid (1.22 g, 10 mmol)
phenyl-2-carbohydrazide (15): 1H NMR (300 MHz, and acid hydrazide 15 (3.41 g, 10 mmol) was ground