May 2008
651
(CO–NH), 1721 (CꢂO), 3327s (NH); 1H-NMR (CDCl3) d: 2.27 (s, 3H, Ar-
CH3), 3.16 (dd, 1H, C2ꢀ-H, Jꢂ3.5, 15.2 Hz), 3.73 (dd, 1H, C2ꢀ-H, Jꢂ9.4,
15.1 Hz), 4.32—4.38 (m, 1H, C1ꢀ-H), 4.44 (d, 1H, C4-H, Jꢂ13.5 Hz), 7.12—
7.81 (m, 8H, Ar-H), 9.55 (bs, 2H, NH); 13C-NMR (CDCl3) d: 23.8 (Ar-
CH3), 53.2 (C-2ꢀ), 58.3 (C-1ꢀ), 63.4 (C-4), 172.8 (C-3, C-5), 203.9 (Ar-CO),
205.1 (Arꢀ-CO), 128.8, 129.6, 130.8, 131.6, 132.7, 134.5, 135.4, 138.2 (aro-
matic carbons). Anal. Calcd for C20H17ClN2O4: C, 62.42; H, 4.45; N, 7.28;
Found: C, 62.58; H, 4.42; N, 7.39.
trione (6a—f) The compound
2
(10 mmol), urea/N,Nꢀ-dimethylurea
(10 mmol), 10% NaOMe (5 ml) and MeOH (10 ml) was refluxed for 10—
12 h. The contents were cooled and poured onto crushed ice containing
conc. HCl. The separated solid was filtered, dried and recrystallized from
MeOH.
5-(1ꢀ,2ꢀ-Dibenzoyl-ethyl)pyrimidine-2,4,6-trione (5a): White solid, yield
72%, mp 203—205 °C; IR (KBr) cmꢁ1: 1656 (CO–NH), 1732 (CꢂO), 3332
1
(NH); H-NMR (CDCl3) d: 3.12 (dd, 1H, C2ꢀ-H, Jꢂ3.7, 15.1 Hz), 3.82 (dd,
General Procedure of Synthesis of 4-(1ꢀ,2ꢀ-Diaroyl-ethyl)isoxazoli-
dine-3,5-dione (4a—f) To a solution of 2 (10 mmol) in MeOH (20 ml),
hydroxylamine hydrochloride (10 mmol) and 10% NaOMe (5 ml) were
added and refluxed for 6—8 h. The reaction mixture was cooled and poured
onto crushed ice containing conc. HCl. The solid separated was filtered,
dried and recrystallized from MeOH.
1H, C2ꢀ-H, Jꢂ9.8, 14.9 Hz), 4.33—4.40 (m, 1H, C1ꢀ-H), 4.46 (d, 1H, C5-H,
Jꢂ13.8 Hz), 7.08—7.63 (m, 10H, Ar-H), 9.21 (bs, 2H, NH); 13C-NMR
(CDCl3) d: 52.2 (C-2ꢀ), 56.5 (C-1ꢀ), 64.1 (C-5), 158.5 (C-2), 164.5 (C-4, C-
6), 202.3 (Ar-CO), 204.2 (Arꢀ-CO), 127.6, 129.4, 130.2, 132.2, 132.9,
133.7, 134.2, 135.4 (aromatic carbons). Anal. Calcd for C20H16N2O5: C,
65.93; H, 4.43; N, 7.69; Found: C, 6.00; H, 4.40; N, 7.75.
4-(1ꢀ,2ꢀ-Dibenzoyl-ethyl)isoxazolidine-3,5-dione (4a): White solid, yield
80%, mp 177—179 °C; IR (KBr) cmꢁ1: 1659 (CO–NH), 1729 (CꢂO), 1737
(CO–O), 3335 (NH); 1H-NMR (CDCl3) d: 3.15 (dd, 1H, C2ꢀ-H, Jꢂ3.4,
15.2 Hz), 3.86 (dd, 1H, C2ꢀ-H, Jꢂ9.4, 14.9 Hz), 4.30—4.36 (m, 1H, C1ꢀ-H),
4.45 (d, 1H, C4-H, Jꢂ13.6 Hz), 7.09—7.94 (m, 10H, Ar-H), 10.15 (bs, 1H,
NH); 13C-NMR (CDCl3) d: 52.9 (C-2ꢀ), 58.5 (C-1ꢀ), 62.6 (C-4), 172.6 (C-
3), 175.2 (C-5), 204.5 (Ar-CO), 205.9 (Arꢀ-CO), 129.5, 130.6, 131.7, 132.1,
132.5, 134.2, 136.3, 137.8 (aromatic carbons). Anal. Calcd for C19H15NO5:
C, 67.65; H, 4.48; N, 4.15; Found: C, 67.71; H, 4.52; N, 4.22.
4-(1ꢀ,2ꢀ-Di(4-methylbenzoyl)-ethyl)isoxazolidine-3,5-dione (4b): White
solid, yield 78%, mp 190—192 °C; IR (KBr) cmꢁ1: 1666 (CO–NH), 1726
(CꢂO), 1740 (CO–O), 3338 (NH); 1H-NMR (CDCl3) d: 2.34 (s, 6H, Ar-
CH3, Arꢀ-CH3), 3.13 (dd, 1H, C2ꢀ-H, Jꢂ3.4, 15.1 Hz), 3.85 (dd, 1H, C2ꢀ-H,
Jꢂ9.7, 15.0 Hz), 4.35—4.41 (m, 1H, C1ꢀ-H), 4.48 (d, 1H, C4-H, Jꢂ13.3 Hz),
7.06—7.97 (m, 8H, Ar-H), 10.21 (bs, 1H, NH); 13C-NMR (CDCl3) d: 22.7
(Ar-CH3, Arꢀ-CH3), 53.4 (C-2ꢀ), 58.6 (C-1ꢀ), 63.3 (C-4), 174.5 (C-3), 176.3
(C-5), 204.1 (Ar-CO), 205.2 (Arꢀ-CO), 129.4, 131.4, 131.8, 132.8, 134.2,
135.5, 137.1, 137.6 (aromatic carbons). Anal. Calcd for C21H19NO5: C,
69.03; H, 5.24; N, 3.83; Found: C, 69.14; H, 5.21; N, 3.78.
4-(1ꢀ,2ꢀ-Di(4-chlorobenzoyl)-ethyl)isoxazolidine-3,5-dione (4c): Colour-
less crystals, yield 81%, mp 211—213 °C; IR (KBr) cmꢁ1: 1662 (CO–NH),
1730 (CꢂO), 1743 (CO–O), 3315 (NH); 1H-NMR (CDCl3) d: 3.15 (dd, 1H,
C2ꢀ-H, Jꢂ3.6, 15.2 Hz), 3.87 (dd, 1H, C2ꢀ-H, Jꢂ9.6, 15.1 Hz), 4.28—4.35
(m, 1H, C1ꢀ-H), 4.45 (d, 1H, C4-H, Jꢂ13.5 Hz), 7.00—7.18 (m, 8H, Ar-H),
10.19 (bs, 1H, NH); 13C-NMR (CDCl3) d: 53.0 (C-2ꢀ), 58.8 (C-1ꢀ), 63.7 (C-
4), 173.4 (C-3), 175.5 (C-5), 204.3 (Ar-CO), 205.7 (Arꢀ-CO), 129.1, 130.9,
131.2, 132.4, 133.3, 134.7, 135.6, 138.5 (aromatic carbons). Anal. Calcd for
C19H13Cl2NO5: C, 56.18; H, 3.23; N, 3.45; Found: C, 56.10; H, 3.25; N,
3.52.
5-(1ꢀ,2ꢀ-Di(4-methylbenzoyl)-ethyl)pyrimidine-2,4,6-trione (5b): White
solid, yield 75%, mp 213—215 °C; IR (KBr) cmꢁ1: 1663 (CO–NH), 1731
(CꢂO), 3344 (NH); 1H-NMR (CDCl3) d: 2.31 (s, 6H, Ar-CH3, Arꢀ-CH3),
3.15 (dd, 1H, C2ꢀ-H, Jꢂ3.9, 15.2 Hz), 3.89 (dd, 1H, C2ꢀ-H, Jꢂ9.9, 15.1 Hz),
4.29—4.37 (m, 1H, C1ꢀ-H), 4.42 (d, 1H, C5-H, Jꢂ13.9 Hz), 7.03—7.74 (m,
8, Ar-H), 9.24 (bs, 2H, NH); 13C-NMR (CDCl3) d: 22.1 (Ar-CH3, Arꢀ-CH3),
52.7 (C-2ꢀ), 55.9 (C-1ꢀ), 64.4 (C-5), 158.3 (C-2), 165.7 (C-4, C-6), 203.1
(Ar-CO), 205.4 (Arꢀ-CO), 128.8, 129.6, 131.4, 132.9, 133.1, 133.5, 134.2,
137.2 (aromatic carbons). Anal. Calcd for C22H20N2O5: C, 67.34; H, 5.14; N,
7.14; Found: C, 67.28; H, 5.12; N, 7.23.
5-(1ꢀ,2ꢀ-Di(4-chlorobenzoyl)-ethyl)pyrimidine-2,4,6-trione (5c): Colour-
less crystals, yield 68%, mp 218—220 °C; IR (KBr) cmꢁ1: 1657 (CO–NH),
1718 (CꢂO), 3348 (NH); 1H-NMR (CDCl3) d: 3.19 (dd, 1H, C2ꢀ-H, Jꢂ3.5,
14.9 Hz), 3.86 (dd, 1H, C2ꢀ-H, Jꢂ9.6, 14.8 Hz), 4.30—4.36 (m, 1H, C1ꢀ-H),
4.41 (d, 1H, C5-H, Jꢂ13.5 Hz), 6.96—7.44 (m, 8H, Ar-H), 9.31 (bs, 2H,
NH); 13C-NMR (CDCl3) d: 52.5 (C-2ꢀ), 56.7 (C-1ꢀ), 64.2 (C-5), 159.2 (C-
2), 164.8 (C-4, C-6), 202.5 (Ar-CO), 204.9 (Arꢀ-CO), 128.6, 129.2, 130.7,
132.2, 133.2, 133.8, 134.5, 138.4 (aromatic carbons). Anal. Calcd for
C20H14Cl2N2O5: C, 55.45; H, 3.26; N, 6.47; Found: C, 55.41; H, 3.30; N,
6.42.
5-(1ꢀ-(4-Methylbenzoyl)-2ꢀ-benzoyl-ethyl)pyrimidine-2,4,6-trione (5d):
White solid, yield 69%, mp 186—188 °C; IR (KBr) cmꢁ1: 1664 (CO–NH),
1
1725 (CꢂO), 3337 (NH); H-NMR (CDCl3) d: 2.28 (s, 3H, Arꢀ-CH3), 3.14
(dd, 1H, C2ꢀ-H, Jꢂ3.7, 15.1 Hz), 3.83 (dd, 1H, C2ꢀ-H, Jꢂ9.7, 14.9 Hz),
4.34—4.39 (m, 1H, C1ꢀ-H), 4.44 (d, 1H, C5-H, Jꢂ13.7 Hz), 7.01—7.48 (m,
9H, Ar-H), 9.26 (bs, 2H, NH); 13C-NMR (CDCl3) d: 23.8 (Arꢀ-CH3), 53.4
(C-2ꢀ), 56.2 (C-1ꢀ), 63.8 (C-5), 159.5 (C-2), 164.3 (C-4, C-6), 201.8 (Ar-
CO), 204.5 (Arꢀ-CO), 128.6, 129.2, 130.2, 131.2, 132.7, 133.4, 134.4, 136.3
(aromatic carbons). Anal. Calcd for C21H18N2O5: C, 66.66; H, 4.79; N, 7.40;
Found: C, 66.75; H, 4.75; N, 7.50.
4-(1ꢀ-(4-Methylbenzoyl)-2ꢀ-benzoyl-ethyl)isoxazolidine-3,5-dione (4d):
White solid, yield 82%, mp 165—167 °C; IR (KBr) cmꢁ1: 1664 (CO–NH),
5-(1ꢀ-(4-Chlorobenzoyl)-2ꢀ-benzoyl-ethyl)pyrimidine-2,4,6-trione
(5e):
1
Colourless crystals, yield 71%, mp 195—197 °C; IR (KBr) cmꢁ1: 1656
(CO–NH), 1727 (CꢂO), 3324 (NH); 1H-NMR (CDCl3) d: 3.10 (dd, 1H,
C2ꢀ-H, Jꢂ3.8, 15.3 Hz), 3.86 (dd, 1H, C2ꢀ-H, Jꢂ9.6, 15.1 Hz), 4.31—4.38
(m, 1H, C1ꢀ-H), 4.48 (d, 1H, C5-H, Jꢂ13.6 Hz), 7.11—7.59 (m, 9H, Ar-H),
9.30 (bs, 2H, NH); 13C-NMR (CDCl3) d: 52.3 (C-2ꢀ), 56.8 (C-1ꢀ), 64.4 (C-
5), 158.8 (C-2), 165.7 (C-4, C-6), 202.6 (Ar-CO), 205.5 (Arꢀ-CO), 127.7,
128.5, 129.7, 131.7, 132.6, 133.4, 134.8, 137.9 (aromatic carbons). Anal.
Calcd for C20H15ClN2O5: C, 60.23; H, 3.79; N, 7.02; Found: C, 60.32; H,
3.86; N, 7.07.
1713 (CꢂO), 1735 (CO–O), 3342 (NH); H-NMR (CDCl3) d: 2.30 (s, 3H,
Arꢀ-CH3), 3.18 (dd, 1H, C2ꢀ-H, Jꢂ3.7, 14.8 Hz), 3.84 (dd, 1H, C2ꢀ-H, Jꢂ9.3,
14.9 Hz), 4.29—4.35 (m, 1H, C1ꢀ-H), 4.41 (d, 1H, C4-H, Jꢂ13.6 Hz), 7.02—
7.20 (m, 9H, Ar-H), 10.14 (bs, 1H, NH); 13C-NMR (CDCl3) d: 23.5 (Arꢀ-
CH3), 53.5 (C-2ꢀ), 58.2 (C-1ꢀ), 63.1 (C-4), 173.9 (C-3), 176.1 (C-5), 204.9
(Ar-CO), 205.8 (Arꢀ-CO), 128.2, 129.4, 130.8, 131.9, 132.6, 133.5, 133.8,
134.8 (aromatic carbons). Anal. Calcd for C20H17NO5: C, 68.37; H, 4.88; N,
3.99; Found: C, 68.46; H, 4.90; N, 3.95.
4-(1ꢀ-(4-Chlorobenzoyl)-2ꢀ-benzoyl-ethyl)isoxazolidine-3,5-dione (4e):
White solid, yield 79%, mp 173—175 °C; IR (KBr) cmꢁ1: 1658 (CO–NH),
1726 (CꢂO), 1745 (CO–O), 3312 (NH); 1H-NMR (CDCl3) d: 3.18 (dd, 1H,
C2ꢀ-H, Jꢂ3.5, 15.2 Hz), 3.83 (dd, 1H, C2ꢀ-H, Jꢂ9.5, 15.1 Hz), 4.32—4.38
(m, 1H, C1ꢀ-H), 4.46 (d, 1H, C4-H, Jꢂ13.5 Hz), 7.02—7.20 (m, 9H, Ar-H),
10.17 (bs, 1H, NH); 13C-NMR (CDCl3) d: 53.7 (C-2ꢀ), 58.1 (C-1ꢀ), 63.8 (C-
4), 172.8 (C-3), 175.7 (C-5), 203.9 (Ar-CO), 205.1 (Arꢀ-CO), 128.7, 130.4,
132.3, 132.8, 133.6, 134.0, 134.5, 138.1 (aromatic carbons). Anal. Calcd for
C19H14ClNO5: C, 61.38; H, 3.80; N, 3.77; Found: C, 61.50; H, 3.85; N, 3.83.
4-(1ꢀ-(4-Chlorobenzoyl)-2ꢀ-(4-methylbenzoyl)-ethyl)isoxazolidine-3,5-
5-(1ꢀ-(4-Chlorobenzoyl)-2ꢀ-(4-methylbenzoyl)-ethyl)pyrimidine-2,4,6-tri-
one (5f): White solid, yield 70%, mp 208—210 °C; IR (KBr): 1668
(CO–NH), 1730 (CꢂO), 3342 (NH) cmꢁ1; 1H-NMR (CDCl3) d: 2.33 (s, 3H,
Ar-CH3), 3.11 (dd, 1H, C2ꢀ-H, Jꢂ3.6, 14.9 Hz), 3.80 (dd, 1H, C2ꢀ-H, Jꢂ9.8,
15.0 Hz), 4.27—4.35 (m, 1H, C1ꢀ-H), 4.51 (d, 1H, C5-H, Jꢂ13.9 Hz), 7.07—
7.66 (m, 8H, Ar-H), 9.28 (bs, 2H, NH); 13C-NMR (CDCl3) d: 23.5 (Ar-
CH3), 52.8 (C-2ꢀ), 57.5 (C-1ꢀ), 63.7 (C-5), 158.4 (C-2), 165.3 (C-4, C-6),
202.9 (Ar-CO), 204.7 (Arꢀ-CO), 128.7, 129.4, 130.9, 131.2, 132.7, 133.2,
134.8, 137.6 (aromatic carbons). Anal. Calcd for C21H17ClN2O5: C, 61.10;
H, 4.15; N, 6.79; Found: C, 61.22; H, 4.18; N, 6.86.
dione (4f): White crystals, yield 77%, mp 180—182 °C; IR (KBr) cmꢁ1
:
1661 (CO–NH), 1721 (CꢂO), 1734 (CO–O), 3319 (NH); 1H-NMR (CDCl3)
d: 2.31 (s, 3H, Ar-CH3), 3.19 (dd, 1H, C2ꢀ-H, Jꢂ3.6, 15.0 Hz), 3.80 (dd, 1H,
C2ꢀ-H, Jꢂ9.4, 14.8 Hz), 4.34—4.39 (m, 1H, C1ꢀ-H), 4.47 (d, 1H, C4-H,
Jꢂ13.7 Hz), 7.02—7.20 (m, 8H, Ar-H), 10.14 (bs, 1H, NH); 13C-NMR
(CDCl3) d: 23.1 (Ar-CH3), 53.5 (C-2ꢀ), 56.4 (C-1ꢀ), 63.5 (C-4), 173.8
(C-3), 176.4 (C-5), 203.4 (Ar-CO), 204.8 (Arꢀ-CO), 129.8, 130.7, 131.4,
132.8, 133.2, 133.9, 134.3, 137.9 (aromatic carbons). Anal. Calcd for
C20H16ClNO5: C, 62.26; H, 4.18; N, 3.63; Found: C, 62.30; H, 4.20; N, 3.60.
General Procedure of Synthesis of 5-(1ꢀ,2ꢀ-Diaroyl-ethyl)pyrimidine-
2,4,6-trione (5a—f)/1,3-Dimethyl-5-(1ꢀ,2ꢀ-diaroyl-ethyl)pyrimidine-2,4,6-
1,3-Dimethyl-5-(1ꢀ,2ꢀ-dibenzoyl-ethyl)pyrimidine-2,4,6-trione
(6a):
White solid, yield 67%, mp 206—208 °C; IR (KBr) cmꢁ1: 1665 (CO–N),
1
1721 (CꢂO); H-NMR (CDCl3) d: 2.80 (s, 6H, N-CH3), 3.15 (dd, 1H, C2ꢀ-
H, Jꢂ3.3, 14.9 Hz), 3.84 (dd, 1H, C2ꢀ-H, Jꢂ9.5, 14.7 Hz), 4.32—4.38 (m,
1H, C1ꢀ-H), 4.44 (d, 1H, C5-H, Jꢂ13.7 Hz), 7.06—7.89 (m, 10H, Ar-H);
13C-NMR (CDCl3) d: 27.7 (N-CH3), 53.6 (C-2ꢀ), 56.9 (C-1ꢀ), 64.1 (C-5),
156.4 (C-2), 167.1 (C-4, C-6), 202.5 (Ar-CO), 204.0 (Arꢀ-CO), 129.1,
130.3, 131.8, 132.4, 132.9, 133.6, 134.5, 135.2 (aromatic carbons). Anal.
Calcd for C22H20N2O5: C, 67.34; H, 5.14; N, 7.14; Found: C, 67.44; H, 5.16;
N, 7.20.