11826
I. Cepanec et al. / Tetrahedron 63 (2007) 11822–11827
4.3.2. 6-Isopropyl-5-methoxycarbonyl-4-(2-methoxy-
phenyl)-3,4-dihydropyrimidin-2(1H)-one (3i). Colourless
needles; mp 248.6–250.4 ꢀC; yield 2.19 g (72%); found: C,
63.0; H, 6.5; N, 9.2. C16H20N2O4 requires C, 63.14; H,
6.62; N, 9.21; Rf (CH2Cl2/2-PrOH, 9.5:0.5) 0.51; nmax
(KBr) 3406, 3223, 3119, 2999, 2960, 2937, 2835, 1709,
1692, 1635, 1597, 1585, 1486, 1463, 1440, 1429, 1391,
1373, 1345, 1313, 1291, 1274, 1239, 1220, 1182, 1109,
1091, 1067, 1046, 1029 cmꢁ1; dH (600 MHz, CDCl3) 8.54
(1H, s, NH), 7.21 (1H, t, J¼7.1 Hz, NH), 7.06–6.84 (4H,
m, arom.), 5.49 (1H, d, J¼2.7 Hz, benzylic), 3.80 (3H, s,
OCH3), 3.47 (3H, s, COOCH3), 1.17 (6H, dd, J1¼7.0 Hz,
J2¼7.0 Hz, CH(CH3)2); dC (600 MHz, CDCl3) 165.5
(COOCH3), 156.5, 156.3, 152.4, 131.0, 128.3, 126.4,
119.9, 111.1, 96.4, 55.1, 50.3, 49.0, 26.9, 19.1, 18.7.
4.3.6. 5-Isobutyloxycarbonyl-6-methyl-4-(1-naphthyl)-
3,4-dihydropyrimidin-2(1H)-one (3m). Colourless nee-
dles; mp 188.9–190.4 ꢀC; yield 2.74 g (81%); found: C,
70.8; H, 6.5; N, 8.2. C20H22N2O3 requires C, 70.99; H,
6.55; N, 8.28; Rf (CH2Cl2/2-PrOH, 9.5:0.5) 0.36; nmax
(KBr) 3232, 3100, 2960, 1705, 1686, 1654, 1600, 1509,
1470, 1436, 1397, 1373, 1334, 1289, 1269, 1243, 1167,
1093, 1074 cmꢁ1; dH (600 MHz, CDCl3) 9.31 (1H, s, NH),
8.32 (1H, d, J¼8.2 Hz, NH), 7.99–7.80 (3H, m, arom.),
7.62–7.39 (4H, m, arom.), 6.09 (1H, d, J¼3.1 Hz, benzylic),
3.64–3.51 (2H, m, CH2CH(CH3)2), 2.41 (3H, s, CH3), 1.50–
1.37 (1H, m, CH2CH(CH3)2), 0.44 (6H, dd, J1¼6.7 Hz, J2¼
6.7 Hz, CH2CH(CH3)2); dC (600 MHz, CDCl3) 165.3
(COOi-Bu), 151.7, 149.4, 140.0, 133.6, 130.1, 128.5,
127.9, 126.1, 125.70, 125.66, 123.9, 123.6, 98.7, 69.1, 49.6,
27.0, 18.52, 18.49, 17.8.
4.3.3. 4-(2,4-Dimethylphenyl)-6-isopropyl-5-methoxy-
carbonyl-3,4-dihydropyrimidin-2(1H)-one (3j). Colour-
less needles; mp 225.6–227.7 ꢀC; yield 1.63 g (54%) at
20 mol % SbCl3, 1.90 g (63%) at 100 mol % SbCl3; found:
C, 67.4; H, 7.2; N, 9.2. C17H22N2O3 requires C, 67.53; H,
7.33; N, 9.27; Rf (CH2Cl2/2-PrOH, 9.5:0.5) 0.53; nmax (KBr)
3364, 3243, 3138, 2973, 2952, 2930, 2876, 1692, 1635,
1456, 1427, 1368, 1338, 1313, 1277, 1221, 1186, 1176,
1135, 1094, 1069 cmꢁ1; dH (600 MHz, CDCl3) 8.88 (1H, s,
NH), 7.62 (1H, s, NH), 7.06 (1H, d, J¼7.6 Hz, arom.), 6.97–
6.94 (2H, m, arom.), 5.38 (1H, d, J¼2.2 Hz, benzylic), 4.21–
4.12 (1H, m, CH(CH3)2), 3.44 (3H, s, COOCH3), 2.37 (3H,
s, CH3), 2.21 (3H, s, CH3), 1.18 (6H, dd, J1¼6.9 Hz, J2¼
6.9 Hz, CH(CH3)2); dC (600 MHz, CDCl3) 165.8 (COOCH3),
156.3, 152.4, 140.2, 136.3, 134.6, 131.0, 127.2, 126.3, 98.2,
50.9, 50.1, 27.0, 20.6, 19.4, 19.0, 18.6.
4.3.7. 4-(9-Anthryl)-6-isopropyl-5-methoxycarbonyl-3,4-
dihydropyrimidin-2(1H)-one (3n). Colourless needles;
mp 254.3–256.1 ꢀC; yield 2.62 g (70%); found: C, 73.8; H,
5.9; N, 7.4. C23H22N2O3 requires C, 73.78; H, 5.92; N,
7.48; Rf (CH2Cl2/2-PrOH, 9.5:0.5) 0.54; nmax (KBr) 3442,
3200, 3090, 2995, 2949, 1730, 1702, 1635, 1526, 1483,
1462, 1425, 1372, 1335, 1302, 1267, 1230, 1185, 1168,
1149, 1099, 1068, 1023 cmꢁ1; dH (600 MHz, CDCl3)
8.42–8.31 (3H, m, NH+arom.), 7.96 (1H, d, J¼8.8 Hz,
NH), 7.52–7.40 (5H, m, arom.), 7.08 (1H, s, arom.), 5.40
(1H, s, benzylic), 4.03–3.91 (1H, m, CH(CH3)2), 2.98 (3H,
s, COOCH3), 1.31 (3H, d, J¼6.9 Hz, CH(CH3)2), 1.21 (3H,
d, J¼7.0 Hz, CH(CH3)2); dC (600 MHz, CDCl3) 165.6
(COOCH3), 151.5, 151.3, 132.3, 130.0, 129.3, 129.0,
126.3, 124.6, 122.8, 100.1, 51.1, 50.4, 27.7, 19.9, 18.9.
4.3.4. 4-(2,6-Dichlorophenyl)-5-isopropoxycarbonyl-6-
methyl-3,4-dihydropyrimidin-2(1H)-one (3k). Colourless
needles; mp 224.9–227.8 ꢀC; yield 2.02 g (59%); found: C,
52.2; H, 4.6; N, 8.1. C15H16N2O3Cl2 requires C, 52.49;
H, 4.70; N, 8.16; Rf (CH2Cl2/2-PrOH, 9.5:0.5) 0.34; nmax
(KBr) 3343, 3146, 2988, 1690, 1645, 1580, 1563, 1514,
4.3.8. 4-(9-Anthryl)-5-benzyloxycarbonyl-6-isopropyl-
3,4-dihydropyrimidin-2(1H)-one (3o). Colourless needles;
mp 203.7–206.1 ꢀC; yield 3.34 g (79%); found: C, 76.5; H,
5.1; N, 6.5. C27H22N2O3 requires C, 76.76; H, 5.25; N,
6.63; Rf (CH2Cl2/2-PrOH, 9.5:0.5) 0.39; nmax (KBr) 3225,
3089, 2965, 1701, 1644, 1526, 1496, 1454, 1446, 1379,
1311, 1290, 1225, 1185, 1158, 1143, 1123, 1087,
1028 cmꢁ1; dH (600 MHz, CDCl3) 9.47 (1H, s, NH), 8.57
(1H, s, NH), 8.47 (2H, s, arom.), 8.09 (2H, s, arom.), 7.72
(1H, s, arom.), 7.48–7.45 (4H, m, arom.), 7.10–7.06 (2H,
m, arom.), 6.98–6.93 (2H, m, arom.), 6.37 (2H, d, J¼
7.5 Hz), 4.50 (2H, s, CH2Ph), 2.27 (3H, s, CH3); dC
(600 MHz, CDCl3) 165.1 (COOBn), 150.5, 146.9, 135.9,
134.9, 131.3, 128.6, 128.0, 127.9, 127.3, 127.0, 125.8,
124.7, 124.2, 99.3, 64.3, 50.0, 17.9.
1437, 1374, 1351, 1305, 1234, 1204, 1095, 1055 cmꢁ1
;
dH (600 MHz, CDCl3) 9.27 (1H, s, NH), 7.63–7.26 (3H,
m, arom.), 6.14 (1H, s, NH), 5.44 (1H, s, benzylic),
4.78–4.70 (1H, m, CH(CH3)2), 2.18 (3H, s, CH3), 1.10
(3H, d, J¼6.3 Hz, CH(CH3)2), 0.66 (3H, d, J¼6.2 Hz,
CH(CH3)2); dC (600 MHz, CDCl3) 164.5 (COOi-Pr),
157.0, 150.7, 137.8, 134.8, 130.1, 129.5, 94.4, 65.8, 52.3,
21.6, 20.9, 18.0.
4.3.5. 6-Isopropyl-5-methoxycarbonyl-4-(1-naphthyl)-
3,4-dihydropyrimidin-2(1H)-one (3l). Colourless needles;
mp 235.3–238.7 ꢀC; yield 1.91 g (59%); found: C, 70.1; H,
6.1; N, 8.5. C19H20N2O3 requires C, 70.35; H, 6.21; N,
8.64; Rf (CH2Cl2/2-PrOH, 9.5:0.5) 0.46; nmax (KBr) 3410,
3233, 3129, 2970, 1694, 1681, 1631, 1509, 1457, 1431,
1410, 1392, 1344, 1317, 1291, 1275, 1263, 1236, 1186,
1132, 1096 cmꢁ1; dH (600 MHz, CDCl3) 9.01 (1H, s, NH),
8.32 (1H, d, J¼8.1 Hz, NH), 8.00–7.73 (3H, m, arom.),
7.62–7.39 (4H, arom.), 6.07 (1H, d, J¼3.4 Hz, benzylic),
4.30–4.21 (1H, m, CH(CH3)2), 3.36 (COOCH3), 1.25 (6H,
dd, J1¼7.0 Hz, J2¼6.9 Hz, CH(CH3)2); dC (600 MHz,
CDCl3) 165.8 (COOCH3), 157.2, 152.4, 139.6, 133.7, 130.1,
128.6, 128.1, 126.2, 125.8, 123.7, 123.6, 97.8, 51.0, 49.7,
27.2, 19.4, 19.1.
4.3.9. 5-Benzyloxycarbonyl-4-(2-methoxyphenyl)-6-
methyl-3,4-dihydropyrimidin-2(1H)-one (3p). Colourless
needles; mp 199.3–200.8 ꢀC; yield 1.80 g (51%) at
20 mol % SbCl3, 2.75 g (78%) at 100 mol % SbCl3; found:
C, 68.2; H, 5.6; N, 7.9. C20H20N2O4 requires C, 68.17; H,
5.72; N, 7.95; Rf (CH2Cl2/MeOH, 9.5:0.5) 0.40; nmax
(KBr) 3239, 3115, 3026, 2954, 2937, 2837, 1721, 1712,
1682, 1639, 1598, 1587, 1487, 1464, 1437, 1380, 1335,
1316, 1283, 1242, 1218, 1186, 1167, 1144, 1100, 1073,
1028, 1051 cmꢁ1; dH (600 MHz, CDCl3) 9.23 (1H, s, NH),
7.34 (1H, s, NH), 7.27–7.24 (4H, m, arom.), 7.07–6.85
(5H, m, arom.), 5.58 (1H, d, J¼2.8 Hz, benzylic), 5.02–
4.93 (2H, m, CH2Ph), 3.72 (3H, s, OCH3), 2.32 (3H, s,
CH3); dC (600 MHz, CDCl3) 165.0 (COOBn), 156.4,