622
Saeed Ali Syed et al.
160.96, 164.51. MS (70 eV): m/z (Irel, %) 289 (39) [M + H]+, 2.1.8 Structure identification of (E)-N-(4-
267 (25), 133 (100): calculated for C13H12N4O4 (288.09):
HRMS: 288.0819.
bromobenzylidene)-2,6-dioxo-1,2,3,6-
tetrahydropyrimidine-4-carbohydrazide (11)
Yield: 59%, m.p.: 177°C. White solid, IR (KBr) (v = cm–1):
1,717, 1,725 (C]O), 3,050 (NH), 3,300 (OH). 1H NMR
(500.133 MHz, DMSO-d6): δ = 6.11 (s, 1H, CH), 7.65 (d, 2H,
j = 8.5 Hz, arom), 7.83 (d, 2H, j = 8.5 Hz, arom), 8.37 (s,
1H, CH), 8.71 (br s, 1H, NH), 10.25 (br s, 1H, NH), 11.25 (br
2.1.5 Structure identification of (E)-N′-(2,6-
dichlorobenzylidene)-2,6-dioxo-1,2,3,6-
tetrahydropyrimidine-4-carbohydrazide (7)
Yield: 69%, m.p.: 211°C. Light yellow solid, IR (KBr) (v = s, 1H, NH). 13C NMR (125.76 MHz, DMSO-d6): δ = 99.83,
cm–1): 1,718, 1,723 (C]O), 3,029 (NH), 3,290 (OH). H 127.41, 129.73, 130.69, 131.86, 132.10 132.50, 145.33,
1
NMR (500.133 MHz, DMSO-d6): δ = 6.16 (s, 1H, CH), 150.88, 151.20, 164.56, 162.07. MS (70 eV): m/z (Irel, %) 337
7.49–7.63 (m, 3H, arom), 7.99, 8.62 (s, 1H, CH), 11.03 (br (30) [M + H]+, 211 (90), 157 (28): calculated for C12H9BrN4O3
s, 1H, NH), 11.37 (br s, 1H, NH), 12.38 (br s, 1H, NH). 13C (335.99): HRMS: 335.9701.
NMR (125.76 MHz, DMSO-d6): δ = 101.29, 129.71 (2×),
130.18, 132.78, 133.11, 134.64, 137.63, 148.91, 157.08,
164.46, 167.07. MS (70 eV): m/z (Irel, %) 327 (39) [M + H]+, 2.1.9 Structure identification of (E)-N-(4-
292 (25), 170 (100): calculated for C12H8Cl2N4O3 (326.00):
HRMS: 326.0736.
chlorobenzylidene)-2,6-dioxo-1,2,3,6-
tetrahydropyrimidine-4-carbohydrazide (12)
Yield: 63%, m.p.: 141°C. White solid, IR (KBr) (v = cm–1):
1,715, 1,730 (C]O), 2,990 (NH), 3,335 (OH). 1H NMR
(500.133 MHz, DMSO-d6): δ = 6.10 (s, 1H, CH), 7.77 (d,
2H, j = 8.5 Hz, arom), 7.90 (d, 2H, j = 8.2 Hz, arom), 8.38
(s, 1H, CH), 8.71 (br s, 1H, NH), 10.13 (br s, 1H, NH), 11.26
2.1.6 Structure identification of (E)-N-(4-
nitrobenzylidene)-2,6-dioxo-1,2,3,6-
tetrahydropyrimidine-4-carbohydrazide (8)
Yield: 69%, m.p.: 169°C. White solid, IR (KBr) (v = cm–1): (br s, 1H, NH). 13C NMR (125.76 MHz, DMSO-d6): δ =
1,715, 1,723 (C]O), 3,039 (NH), 3,290 (OH). 1H NMR 101.04, 128.97 (2×), 129.53 (2×), 130.50, 133.09, 145.04,
(500.133 MHz, DMSO-d6): δ = 5.94 (s, 1H, CH), 7.83 (s, 149.20, 151.28, 161.05, 164.48. MS (70 eV): m/z (Irel, %)
1H, arom), 8.34 (m, 3H, CH, 2× arom), 8.74 (s, 1H, arom), 276 (90) [M − OH]+, 247 (45), 110 (100): calculated for
10.12 (br s, 1H, NH), 10.72 (br s, 1H, NH), 11.26 (br s, 1H, C12H9ClN4O3 (292.04): HRMS: 292.0390.
NH). 13C NMR (125.76 MHz, DMSO-d6): δ = 103.0, 123.16,
131.16 (2×), 134.91 (2×), 144.20, 149.51, 151.33, 151.90,
164.16, 167.63. MS (70 eV): m/z (Irel, %) 304 (41) [M + 2.1.10 X-ray crystallographic studies of compounds 2,
H]+, 298 (78), 176 (100): calcd for C12H9N5O5 (303.06):
HRMS: 303.0541.
3, and 4
Crystals of compound 2 (Scheme 1) were obtained by
crystallization from ethanol–water (3:1) via slow solvent
evaporation. The crystallographic data for compound 2
have been deposited at the Cambridge Crystallographic
Data Center (deposit CCDC 1483501). Brown needles of
compound 3 (Scheme 1) were obtained by crystallization
2.1.7 Structure identification of (E)-N-(3,4-
dichlorobenzylidene)-2,6-dioxo-1,2,3,6-
tetrahydropyrimidine-4-carbohydrazide (10)
Yield: 55%, m.p.: 157°C. White solid, IR (KBr) (v = cm–1): from ethanol–water via slow solvent evaporation. The
1,722, 1,723 (C]O), 3,031 (NH), 3,290 (OH). 1H NMR crystallographic data for compound
3 have been
(500.133 MHz, DMSO-d6): δ = 5.99 (s, 1H, CH), 7.73 (m, deposited at the Cambridge Crystallographic Data Center
2H, arom), 7.99 (s, 2H, arom), 8.38 (s, 1H, CH), 11.03 (br (deposit CCDC 150815). Yellow crystals of compound 4
s, 1H, NH), 11.27 (br s, 1H, NH), 12.33 (br s, 1H, NH). 13C (Scheme 1) were obtained by crystallization from hot
NMR (125.76 MHz, DMSO-d6): δ = 101.17, 127.55, 129.44, ethanol via slow solvent evaporation. The compound
130.60, 132.27, 133.36, 134.74, 135.61, 147.78, 157.67, crystallized with two molecules of water in the crystal
164.48, 166.82. MS (70 eV): m/z (Irel, %) 289 (39) [M − lattice. The crystallographic data for compound 4 have
Cl]+, 267 (25), 133 (100): calcd for C12H8Cl2N4O3 (326.00): been deposited at the Cambridge Crystallographic Data
HRMS: 326.0317.
Center (deposit CCDC 1483500).