Mendeleev Commun., 2008, 18, 102–104
C(8)
C(7)
Cl(1)
C(8)
C(9)
C(9)
C(7)
C(6)
O(1)
N(1)
C(4)
C(6)
O(1)
O(2)
N(2)
C(4)
C(1)
C(3)
N(1)
C(1)
O(2)
C(5)
C(5)
C(2)
N(2)
C(2)
C(3)
O(4)
O(3)
O(3)
Figure 2 Molecular structure of 5a. Selected bond lengths (Å) and bond
angles (°): O(3)–C(2) 1.211(2), O(2)–N(2) 1.3745(17), O(1)–C(1) 1.201(2),
N(2)–C(2) 1.337(2), N(2)–C(1) 1.404(2), N(1)–C(1) 1.332(2), N(1)–C(3)
1.447(2); C(2)–N(2)–O(2) 123.68(14), C(2)–N(2)–C(1) 114.74(15), O(2)–
N(2)–C(1) 121.19(16), C(1)–N(1)–C(3) 113.50(16).
Figure 1 Molecular structure of 4c. Selected bond lengths (Å) and
bond angles (°): Cl(1)–C(7) 1.7402(13), O(1)–C(1) 1.2300(15), O(2)–N(2)
1.4047(14), O(3)–C(2) 1.3874(14), O(4)–C(3) 1.4203(14), N(1)–C(1)
1.3462(16), N(1)–C(3) 1.4516(15), N(2)–C(1) 1.3822(16), N(2)–C(2)
1.4524(16), C(2)–C(3) 1.5587(17), C(3)–C(4) 1.5116(17); O(1)–C(1)–N(1)
126.60(11), O(1)–C(1)–N(2) 125.26(11), O(2)–N(2)–C(2) 115.14(10),
O(2)–N(2)–C(1) 113.74(10), C(1)–N(2)–C(2) 108.70(10), C(1)–N(1)–C(3)
112.26(10), O(3)–C(2)–N(2) 111.54(10), O(3)–C(2)–C(3) 112.95(11),
O(4)–C(3)–C(4) 109.77(10), N(1)–C(3)–C(2) 100.17(9), N(2)–C(2)–C(3)
101.14(9).
more favourable conjugation of the lone pair of the N(2) atom
with the C(2)=O(3) carbonyl group.
In compound 4c, the ordinary bonds O(3)–C(2) and O(4)–C(3)
are somewhat different: the bond O(4)–C(3) [1.4203(14) Å] is
longer than the bond O(3)–C(2) [1.3874(14) Å]. And vice versa,
the bond O(3)–H(3) (0.873 Å) is longer than the bond O(4)–H(4)
(0.823 Å). The length differences of these O–C and O–H bonds
can be regarded as an argument toward the third stage of the
mechanism of arylglyoxal condensation with N-hydroxyurea 2
(Scheme 1).
†
N-Hydroxy-N-[hydroxy(p-methylbenzoyl)]methylurea 3b. A solution
of freshly obtained N-hydroxyurea 2 (0.359 g, 4.718 mmol) in H2O
(5 ml) was added to a warm (45–50 °C) solution of p-tolylglyoxal 1b
hydrate (0.784 g, 4.718 mmol) in water (25 ml). The reaction mixture
was stirred at 20 °C for 60 h; then, it was kept for 24 h. The precipitate
was filtered off and washed with water (4 ml) to yield 0.345 g (32.6%)
of 3b, colourless solid, mp 134–136 °C (decomp.). 1H NMR [300 MHz,
(CD3)2SO] d: 2.38 (s, 3H, Me), 5.95 (d, 1H, CHOH, 3J 7.5 Hz), 6.49 (d,
1H, CHOH, 3J 7.5 Hz), 6.51 (br. s, 2H, NH2), 7.31 [d, 2H, C(3)H,
In a similar manner, the other hydantoins were obtained. 3-Hydroxy-
5-(p-chlorophenyl)hydantoin 5c, monohydrate, yield 74%, colourless
crystals, mp 132–134 °C (decomp.). 1H NMR [(CD3)2SO] d: 5.29 (s, 1H,
CH), 7.38 [d, 2H, C(2)H, C(6)H, 3J 8.4 Hz], 7.51 [d, 2H, C(3)H, C(5)H,
3J 8.4 Hz], 8.77 (s, 1H, NH), 10.64 (br. s, 1H, OH). IR (n/cm–1): 3290
(NH), 1765 (C=O), 1720 (C=O). MS [FAB, H+, m/z, Irel (%)]: 229
[M + H]+ (30.8), 227 [M + H]+ (100). Found (%): C, 43.98; H, 3.85. Calc.
for C9H7N2O3Cl·H2O (%): C, 44.19; H, 3.71. 3-Hydroxy-5-(2'-thienyl)-
hydantoin 5d, monohydrate, yield 62%, yellowish crystals, unstable,
mp 107–108 °C (decomp.). 1H NMR [300 MHz, (CD3)2SO] d: 5.56 (s, 1H,
CH), 7.07 [td, 1H, C(4)H, 3J 5.1 Hz, 4J 1.5 Hz], 7.17 [dd, 1H, C(3)H,
3
3
C(5)H, J 7.8 Hz], 7.88 [d, 2H, C(2)H, C(6)H, J 7.8 Hz], 9.28 (s, 1H,
NOH). IR (n/cm–1): 3415 (OH), 3340, 3280 (NH2), 1685 (C=O), 1645
(C=O). MS [FAB, H+, m/z, Irel (%)]: 225 [M + H]+ (41.8), 207 (16.4),
164 (97.5), 119 (100). Found (%): N, 12.20. Calc. for C10H12N2O4 (%):
N, 12.49. The water filtrate was concentrated in vacuo (2 Torr), the
formed precipitate was filtered off to yield 0.490 g (46.3%) of 3-hydroxy-
5-(p-tolyl)hydantoin 5b monohydrate, colourless crystals, mp 136–139 °C
1
(decomp.). H NMR [300 MHz, (CD3)2SO] d: 2.32 (s, 3H, Me), 5.18 (s,
4
3
3J 3.6 Hz, J 1.5 Hz], 7.57 [dd, 1H, C(5)H, J 5.1 Hz, 4J 1.5 Hz], 8.91
(br. s, 1H, NH), 10.68 (br. s, 1H, OH). IR (n/cm–1): 3520 (OH), 3265
(NH), 1775 (C=O), 1723 (C=O). MS [EI, m/z, Irel (%)]: 198 [M]+ (37.3),
181 (51.0), 170 (19.1), 111 (100). Found (%): N, 12.73. Calc. for
C7H6N2O3S·H2O (%): N, 12.96.
1H, CH), 7.21 [d, 2H, C(3)H, C(5)H, 3J 9.3 Hz], 7.24 [d, 2H, C(2)H,
C(6)H, 3J 9.3 Hz], 8.69 (s, 1H, NH), 10.56 (br. s, 1H, OH). IR (n/cm–1):
3570 (OH), 3270 (NH), 1770 (C=O), 1720 (C=O). MS [FAB, H+, m/z,
Irel (%)]: 207 [M + H]+ (100). Found (%): C, 53.65; H, 5.51; N, 12.38.
Calc. for C10H10N2O3·H2O (%): C, 53.67; H, 5.39; N, 12.49.
‡
Crystal data for 4c: crystals were grown from THF–C6H14 at –20 °C,
C9H9ClN2O4·2H2O, tetragonal, space group P421c, a = 17.1691(2),
3,4,5-Trihydroxy-5-(p-chlorophenyl)imidazolidin-2-one 4c. To a solu-
tion of freshly obtained N-hydroxyurea 2 (0.230 g, 3.00 mmol) in water
(15 ml) the hydrate of p-chlorophenylglyoxal 1c (0.560 g, 3.00 mmol)
was added, the mixture was vigorously stirred at 20 °C for 24 h, kept
for 14 days; then, negligible precipitate was filtered off and the filtrate
was concentrated in vacuo (1 Torr). The precipitated solid was filtered
off yielding 0.501 g (59.5%) of 4c dihydrate, colourless crystals,
–
b = 17.1691(2) and c = 8.2700(1) Å, a = 90°, b = 90° and g = 90°,
V = 2437.81(5) Å3, Mr = 280.66, Z = 8, dcalc = 1.529 g cm–3, m(MoK ) =
= 0.336 mm–1, F(000) = 1168.
Crystal data for 5a: crystals were grown from THF–CH2Cl2 at –20 °C,
C9H8N2O3·H2O, monoclinic, space group P21/c, a = 19.427(5), b = 6.1575(8)
and c = 7.9395(11) Å, a = 90°, b = 96.132(15)°, g = 90°, V = 944.3(3) Å3,
Mr = 210.19, Z = 4, dcalc = 1.479 g cm–3, m(MoK ) = 0.118 mm–1, F(000) =
= 440. X-ray diffraction study of compounds 4c and 5a was performed
at 298 K on a Xcalibur 3 diffractometer (graphite monochtomated MoK
radiation, CCD detector, w and j-scans, 2q = 64.94° for 4c and 52.00°
for 5a). Structures were solved by direct methods and refined by a full-
matrix least squares procedure in an anisotropic approximation for non-
hydrogen atoms using the SHELX-97 program package.7 Positions of
non-hydrogen atoms were initially located from the difference electron
density maps and further included into refinement in riding model
approximation with Uiso(H) = nUeq(carrier atom) with n = 1.5 for methyl,
hydroxy groups and water molecules and n = 1.2 for the remaining
H-atoms. In the structure of 4c hydrogen atoms of O(4) hydroxy group
and O(2W) water molecule were found to be disordered over two posi-
tions having equal occupancy. Refinement against F2 in an anisotropic
approximation (the hydrogen atoms isotropic in the riding model) by a
full matrix least-squares method for 4299 reflections was carried out to
wR2 = 0.083 [R1 = 0.031 for 3445 reflections with F > 4s(F), S = 1.06]
for 4c and for 1788 reflections was carried out to wR2 = 0.064 [R1 = 0.037
for 973 reflections with F > 4s(F), S = 1.00] for 5a.
1
mp 103–106 °C (THF–C6H14). H NMR [300 MHz, (CD3)2SO] d: 4.52
(d, 1H, CHOH, 3J 7.2 Hz), 6.23 (s, 1H, OH), 6.48 (d, 1H, CHOH,
3
3J 7.2 Hz), 7.49 [d, 2H, C(2)H, C(6)H, J 8.4 Hz], 7.52 [d, 2H, C(3)H,
C(5)H, 3J 8.4 Hz], 8.10 (br. s, 1H, NH), 9.07 (s, 1H, NOH). IR (n/cm–1):
3605 (OH), 3475 (OH), 3240 (NH), 1720 (C=O). MS [FAB, H+, m/z,
Irel (%)]: 247 [M + H]+ (32.3), 245 [M + H]+ (100), 229 (17.2), 227
(51.5). Found (%): N, 9.82. Calc. for C9H9ClN2O4·2H2O (%): N, 9.98.
3-Hydroxy-5-phenylimidazolidine-2,4-dione 5a. A solution of freshly
obtained N-hydroxyurea 2 (0.190 g, 2.5 mmol) in H2O (5 ml) was added
to a warm (40–45 °C) solution of the hydrate of phenylglyoxal 1a (0.381 g,
2.5 mmol) in water (5 ml). The reaction mixture was stirred at 18 °C for
2 h; then, it was kept for 22 h. Water was removed in vacuo (2 Torr), the
residue was twice extracted by Et2O (15 ml). The precipitated crystals
were filtered off and dried in vacuo, yielding 0.408 g (77%) of the mono-
hydrate of 5a, colourless crystals, after second crystallization (THF–C6H14)
mp 175–176 °C (decomp.). 1H NMR [300 MHz, (CD3)2SO] d: 5.24 (s, 1H,
PhCH), 7.30–7.50 (m, 5H, Ph), 8.74 (s, 1H, NH), 10.60 (br. s, 1H,
NOH). IR (n/cm–1): 3570 (OH), 3280 (NH), 1770 (C=O), 1720 (C=O).
MS [EI, m/z, Irel (%)]: 193 [M + H]+ (0.7), 192 [M]+ (4.0), 176 (40.3), 175
(7.7), 174 (14.7), 164 (8.2), 147 (9.0), 133 (14.5), 132 (11.1), 119 (6.8),
106 (11.4), 105 (86.8), 104 (100), 103 (77.9), 91 (9.2), 78 (27.3), 77
(67.2), 70 (18.0), 59 (20.0). MS [FAB, Na+, m/z, Irel (%)]: 215 [M + Na]+
(54.3), 193 [M + H]+ (100), 176 (33.7). Found (%): C, 51.77; H, 4.61;
N, 13.55. Calc. for C9H8N2O3·H2O (%): C, 51.43; H, 4.80; N, 13.33.
CCDC 659260 and 617196 contain the supplementary crystallographic data
for this paper. These data can be obtained free of charge from The Cambridge
For details, see ‘Notice to Authors’, Mendeleev Commun., Issue 1, 2008.
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