Molecules 2019, 24, 1066
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3
.1.6. 5-(5-((5-(3,5-Dinitrophenyl)-1,3,4-thiadiazol-2-yl)amino)-1,3,4-thiadiazol-2(3H)-ylidene)
pyrimidine-2,4,6(1H,3H,5H)-trione (8)
To a solution of compound 2 (3.41 g, 0.01 mol) in methanol (30 mL), 5-[bis(methylthio)-
methylene] barbituric acid (7) (2.32 g, 0.01 mol) was added with stirring and refluxed for 5 h. The
reaction mixture was left to cool and the separated precipitate was filtered off and recrystallized
−
1
from dioxane to give compound 8. Yield 67%, m.p. 293–295 °C, IR (KBr, cm ): ν = 3322–3189 (NH),
1
1
1
1
4
1
744, 1678, 1655 (3 C=O). H-NMR (400 MHz, ppm, DMSO-d
6
): δ = 8.70, 9.14, 9.30 (3s, 3H, Ph-H), 9.34,
1
3
1.19, 12.67, 12.78 (4s, 4H, 4NH, D
2
O exchangeable). C-NMR (100 MHz, ppm, DMSO-d ): δ = 113.7,
6
27.5, 128.2, 130.7, 132.3, 146.4, 148.1, 154.8, 157.2, 162.6, 167.2, 167.8 (14 C). MS (EI, 70 eV): m/z (%) =
+
77 [M , 23]. Analysis for C14
H
7N
9
O7
S2 (477.39): Calcd. C, 35.22; H, 1.48; N, 26.41. Found: C, 34.88; H,
.70; N, 26.81.
3
.1.7. 3-[5-(3,5-Dinitrophenyl)-1,3,4-thiadiazol-2-yl]-2-hydrazonothiazolidin-4-one (9)
A mixture of thiosemicarbazide 2 (3.41 g, 0.01 mol) and chloroacetic acid (1 mL, 0.01 mol),
sodium acetate (2.46 g, 0.03 mol) in acetic acid (20 mL) was refluxed for 6 h, cooled, and poured on
water/ice. The obtained solid was filtered off, washed with water, and recrystallized from acetic acid
−
1
to produce thiazolidin-4-one derivative 9. Yield 78%, m.p. 246–248 °C, IR (KBr, cm ): ν = 3378, 3254
1
(
NH
CH , thiazolidinone), 6.41 (s, 2H, NH
100 MHz, ppm, DMSO-d ): δ = 31.2, 126.9, 129.6, 131.5, 133.8, 147.5, 150.4, 155.2, 177.7 (11 C). MS (EI,
2
), 2909 (C‒Haliph), 1681 (C=O), 1623 (C=N). H-NMR (400 MHz, ppm, DMSO-d
6
): δ = 3.86 (s, 2H,
1
3
2
2
, D O exchangeable), 8.77, 9.17, 9.28 (3s, 3H, Ph-H). C-NMR
2
(
6
+
7
0 eV): m/z (%) = 381 [M , 20]. Analysis for C11
H
7N
7O
5
S (381.34): Calcd. C, 34.65; H, 1.85; N, 25.71.
2
Found: C, 35.01; H, 2.12; N, 26.03.
3
.1.8. N-Acetyl-N-[3-(5-(3,5-dinitrophenyl)-1,3,4-thiadiazol-2-yl]-4,6-dioxo-2-thioxotetrahydro-
pyrimidin-1(2H)-yl)acetamide (10)
A mixture of 2 (3.41 g, 0.01 mol), malonic acid (1.04 g, 0.01 mol) and acetyl chloride (8 mL) was
refluxed for 10 h. The mixture was poured into cold water with stirring; the precipitated solid was
filtered off and crystallized from dioxane to give compound 10. Yield 59%, m.p. 271–273 °C, IR (KBr,
−
1
1
cm ): ν = 2944 (C‒Haliph), 1710, 1691, 1661 (3 C=O), 1616 (C=N). H-NMR (400 MHz, ppm, DMSO-d
δ = 2.72 (s, 6H, 2CH ), 3.23 (s, 2H, CH
, pyrimidine), 8.73, 9.14, 9.32 (3s, 3H, Ph-H). 13C-NMR (100
MHz, ppm, DMSO-d
6
):
3
2
6
): δ = 24.1, 41.9, 127.5, 129.9, 132.5, 137.6, 148.1, 151.3, 163.5, 164.8, 168.5, 175.9
+
(
16 C). MS (EI, 70 eV): m/z (%) = 493 [M , 18]. Analysis for C16
H11
N7
O8
S2 (493.43): Calcd. C, 38.95; H,
2
.25; N, 19.87. Found: C, 39.31; H, 2.00; N, 20.20.
3
.1.9. 1-[5-(3,5-Dinitrophenyl)-1,3,4-thiadiazol-2-yl]-3-phenylthiourea (11)
To aminothiazole derivative 1 (2.67 g, 0.01 mol) in dry dioxane (30 mL) and phenylisothio-
cyanate (0.01 mol, 1.35 g), anhydrous potassium carbonate (1.38 g, 0.01 mol) was added with stirring
and refluxed for 12 h, cold to room temperature then poured over ice/water. The obtained solid was
filtered off, dried, and crystallized from dioxane to produce 11. Yield 81%, m.p. 264–266 °C, IR (KBr,
−
1
1
cm ): ν = 3329, 3256 (2NH), 3080 (C‒Harom.), 1626 (C=N). H-NMR (400 MHz, ppm, DMSO-d
6): δ =
7
.45–7.89 (m, 5H, Ph-H), 8.68, 9.18, 9.29 (3s, 3H, Ph-H), 10.49, 11.33 (2s, 2H, 2NH, D O exchangeable).
2
13C-NMR (100 MHz, ppm, DMSO-d
6
): δ = 127.3, 129.5, 131.6, 132.5, 134.1, 137.8, 147.7, 150.9, 154.5,
+
1
4
59.2, 182.9 (15 C). MS (EI, 70 eV): m/z (%) = 402 [M , 16]. Analysis for C15
H
10N
6
O4
S2 (402.40): Calcd. C,
4.77; H, 2.50; N, 20.89 Found: C, 45.08; H, 2.77; N, 21.21.
3
.1.10. N-[5-(3,5-Dinitrophenyl)-1,3,4-thiadiazol-2-yl]-3,4-diphenylthiazol-2(3H)-imine (12)
A mixture of 11 (4.02 g, 0.01 mol) and phenacyl bromide (1.99 g, 0.01 mol) in EtOH (50 mL), in
the presence of TEA (0.5 mL), was refluxed for 10 h, then cooled to r.t. The formed solid was filtered
off, washed with water, dried, and crystallized from ethanol to produce imine derivative 12. Yield
−
1
1
5
1%, m.p. 251–253 °C, IR (KBr, cm ): ν = 3061 (C‒Harom.), 1629 (C=N). H-NMR (400 MHz, ppm,