Huang and Liu
(
C
79), 187 (24), 121 (17), 77 (31). Elemental Anal. Calcd for
OS: C 61.09; H 3.73; N 12.95. Found: C 61.38; H 3.92;
N 12.86.
-Meth yl-4H-p yr im id o[2,1-b]ben zoth ia zol-4-on e (17c):
(100), 112 (28), 95 (10), 56 (83). Elemental Anal. Calcd for
11
H
8
N
2
C
8
H
11
N
3
OS: C 48.71; H 5.62; N 21.30. Found: C 48.68; H 5.72;
N 21.28.
1-(N-Ben zylid en ea m in o)-1,6-d ih yd r o-2-m et h ylt h io-6-
oxo-p yr im id in e (20b): White solid. Mp 118-120 °C. H NMR
CDCl ) δ 2.50 (s, 3H), 6.28 (d, 1H, J ) 6.4 Hz), 7.48-7.55 (m,
3H), 7.72 (d, 1H, J ) 6.4 Hz), 7.87-7.90 (m, 2H), 9.26 (s, 1H).
6
1
1
Light yellow solid. Mp 106-108 °C. H NMR (CDCl
(
7
2
1
1
intensity) 216 (M , 97), 188 (100), 161 (14), 146 (12), 121 (21),
1
6
3
) δ 2.62
(
3
s, 3H), 6.33 (d, 1H, J ) 6.52 Hz), 7.31-7.39 (m, 2H), 7.45-
.47 (m, 1H), 7.85 (d, 1H, J ) 6.52 Hz). 1 C NMR (CDCl
3
3
) δ
1
3
C NMR (CDCl ) δ 14.761, 110.903, 128.956, 129.138, 129.733,
3
4.259, 109.217, 119.269, 125.413, 127.250, 130.964, 131.169,
1
32.706, 150.859, 157.252, 159.418, 165.353. IR νmax 3052,
34.382, 151.255, 160.819, 163.111. IR νmax 2930, 1694, 1573,
-
1
-
1
2928, 1679, 1610, 1597, 1574, 1471, 1301, 1287, 1224 cm
.
497, 1470, 1381, 1280, 1243, 987, 813, 755 cm . MS m/z (rel
+
+
MS m/z (rel intensity) 246 (M , 18), 245 (3), 230 (6), 171 (0.60),
1
42 (100), 112 (35), 95 (24), 77 (24), 51 (25). Elemental Anal.
Calcd for C12 OS: C 58.76; H 4.52; N 17.13. Found: C
8.79; H 4.67; N 17.05.
03 (17), 77 (41). Elemental Anal. Calcd for C11
1.09; H 3.73; N 12.95. Found: C 61.38; H 3.92; N 12.86.
H-P yr im id o[2,1-b]ben zoth ia zol-4-on e (17d ): Light yel-
8 2
H N OS: C
11 3
H N
5
4
2
6
1
1-(N-4-Ch lor op h en ylm eth ylid en ea m in o)-1,6-d ih yd r o-
low solid. Mp 166-168 °C (lit. mp 168 °C) H NMR (CDCl
δ 6.43 (d, 1H, J ) 6.52 Hz), 7.49-7.57 (m, 2H), 7.69-7.71 (m,
1
1
2
9
3
)
2
-m eth ylth io-6-oxo-p yr im id in e (20c): Light yellow needles.
1
Mp 146-148 °C. H NMR (CDCl
3
) δ 2.49 (s, 3H), 6.27 (d, 1H,
H), 7.94 (d, 1H, J ) 6.52 Hz), 9.10-9.12 (m, 1H). IR νmax 1682,
1
J ) 6.42 Hz), 7.45 (dd, 2H, J ) 6.76, 1.72 Hz), 7.73 (d, 1H, J
6.42 Hz), 7.80-7.83 (dd, 2H, J ) 6.76, 1.72 Hz), 9.32 (s,
H). 13C NMR (CDCl
-
577, 1499, 1256, 994, 827, 759 cm . MS m/z (rel intensity)
)
+
02 (M , 100), 174 (98), 146 (12), 134 (11), 120 (10), 108 (9),
1
1
3
1
2
3
) δ 14.792, 110.937, 129.345, 130.213,
0 (11), 69 (15).
31.323, 138.869, 150.884, 159.540, 163.346, 164.035. IR νmax
8
-Ch lor o-4H-p yr im id o[2,1-b]ben zoth ia zol-4-on e (17e):
300, 3198, 2927, 1676, 1607, 1593, 1568, 1478, 1405, 1314,
1
Light yellow solid. Mp 198-200 °C. H NMR (CDCl
(
(
)
1
IR νmax 3068, 1680, 1575, 1494, 1406, 1284, 1247, 989, 812,
7
3
Anal. Calcd for C10
Found: C 50.61, H 2.38, N 11.79.
-Br om o-4H-p yr im id o[2,1-b]ben zoth ia zol-4-on e (17f):
Light yellow solid. Mp 200-202 °C. H NMR (CDCl
(
1
3
) δ 6.42
d, 1H, J ) 6.52 Hz), 7.48-7.52 (dd, 1H, J ) 9, 2.1 Hz), 7.68
d, 1H, J ) 2.1 Hz), 7.94 (d, 1H, J ) 6.52 Hz), 9.02 (d, 1H, J
9 Hz). C NMR (CDCl ) δ 109.656, 121.084, 121.579,
3
25.809, 127.446, 133.122, 134.544, 151.976, 160.731, 161.898.
-1
+
292, 1092, 823 cm . MS m/z (rel intensity) 279 (M , 1.53),
+
81 (M + 2, 0.55), 264 (5), 142 (100), 112 (45), 95 (35), 75
OSCl: C 51.52; H
3.60; N 15.02. Found: C 51.64; H 3.49; N 15.22.
-[N(4-Ch lor op h en yl)eth ylid en ea m in o]-1,6-d ih yd r o-2-
m eth ylth io-6-oxo- p yr im id in e (20d ): Light yellow needles.
10 3
(29). Elemental Anal. Calcd for C12H N
1
3
1
-
1
+
+
39 cm . MS m/z (rel intensity) 236 (M , 100), 238 (M + 2,
1
Mp 134-136 °C. H NMR (CDCl
3
) δ 2.23 (s, 3H), 2.52 (s, 3H),
7), 208 (95), 210 (36), 173 (20), 133 (27), 107 (14). Elemental
6
.28 (d, 1H, J ) 6.4 Hz), 7.44 (d, 2H, J ) 8.6 Hz), 7.80 (d, 1H,
H
5
ClN
2
OS: C 50.75; H 2.13; N 11.84.
13
J ) 6.4 Hz), 7.95 (d, 2H, J ) 8.6 Hz). C NMR (CDCl
1
3
) δ
4.426, 17.146, 110.156, 128.941, 129.223, 133.954, 138.506,
8
151.444, 156.812, 161.516, 176.558. IR νmax 3062, 2922, 1681,
1
-1
) δ 6.41
1487, 1368, 1334, 1287, 1141, 1092 cm . MS m/z (rel intensity)
3
+
+
d, 1H, J ) 6.52 Hz), 7.63-7.65 (dd, 1H, J ) 9, 2 Hz), 7.83 (d,
293 (M , 11), 295 (M + 2, 3.88), 278 (100), 280 (37), 183 (14),
H, J ) 2 Hz), 7.94 (d, 1H, J ) 6.52 Hz), 8.98 (d, 1H, J ) 9
152 (51), 154 (17), 112 (67), 75 (40). Elemental Anal. Calcd
1
3
Hz). C NMR (CDCl
3
) δ 108.854, 119.801, 120.510, 123.610,
25.259, 129.445, 134.145, 151.191, 159.920, 160.953. IR νmax
103, 1681, 1577, 1493, 1402, 1284, 1248, 990, 826, 811, 790,
12 3
for C13H N OSCl: C 53.15; H 4.12; N 14.30. Found: C 53.51;
H 3.94; N 14.30.
1-(N-P h en ylp r op ylid en ea m in o)-1,6-d ih yd r o-2-m et h -
ylth io-6-oxo-p yr im id in e (20e): White solid. Mp 160-162 °C.
1
3
7
1
-
1
+
+
32 cm . MS m/z (rel intensity) 280 (M , 100), 282 (M + 2,
00), 254 (78), 252 (78), 173 (40), 133 (37), 69 (29). Elemental
1
3
H NMR (CDCl ) δ 1.05 (t, 3H, J ) 7.6 Hz), 2.51(s, 3H), 2.60
Anal. Calcd for C10
C 42.95; H 1.83; N 9.78.
-Meth yl-5H-th iazolo[3,2-a ]pyr im idin -5-on e (17g): Light
yellow solid. Mp 126-128 °C (lit. mp 128-129 °C). H NMR
(
H
5
N
2
OS: C 42.72; H 1.79; N 9.96. Found:
(m, 2H), 6.28 (d, 1H, J ) 6.43 Hz), 7.46-7.55 (m, 3H), 7.80 (d,
13
1H, J ) 6.43 Hz), 7.93(m, 2H). C NMR (CDCl
4.386, 23.736, 110.118, 128.243, 128.718, 131.851, 134.346,
151.424, 157.181, 161.478, 183.579. IR νmax 3054, 2928, 1686,
3
) δ 11.558,
1
3
2
7
1
-
1
1
586, 1567, 1480, 1444, 1368, 1336, 1316 cm . MS m/z (rel
CDCl
3
) δ 2.82 (d, 3H, J ) 1.32 Hz), 6.19 (d, 1H, J ) 6.52 Hz),
+
.44 (t, 1H, J ) 1.32 Hz), 7.85 (d, 1H, J ) 6.52 Hz). 1 C NMR
3
intensity) 321 (M , 13), 292 (27), 244 (58), 180 (42), 165 (31),
15 3
12 (64), 91 (23), 77 (100). Elemental Anal. Calcd for C18H N -
6
1
(CDCl
3
) δ 18.664, 105.835, 107.420, 136.876, 152.466, 161.524,
OS: C 67.27; H 4.70; N 13.07. Found: C 67.45; H 4.54; N 12.96.
1-(N-Dip h en ylm eth ylid en ea m in o)-1,6-d ih yd r o-2-m eth -
ylth io-6-oxo-p yr im id in e (20f): White solid. Mp 96-98 °C.
1
1
1
65.234. IR νmax 3113, 1670, 1617, 1595, 1481, 1417, 1284,
235, 1147, 968, 812, 761 cm . MS m/z (rel intensity) 166 (M ,
-1
+
00), 138 (72), 93 (18), 71 (29), 72 (21), 67 (15), 52 (13), 45
1
H NMR (CDCl ) δ 2.55 (s, 3H), 5.98 (d, 1H, J ) 6.4 Hz), 7.32-
3
(
32).
Gen er a l P r oced u r e for th e Solid -P h a se Syn th esis of
-(N-Alk ylid en e or ben zylid en ea m in o)-1,6-d ih yd r o-2-m e-
7
1
1
1
3
.39 (m, 4H), 7.40-7.44 (m, 3H), 7.53-7.55 (m, 1H), 7,59 (d,
13
H, J ) 6.4 Hz), 7.77-7.79 (m, 2H). C NMR (CDCl ) δ 14.441,
3
1
10.106, 127.486, 128.003, 128.447, 130.134, 130.228, 132.596,
33.780, 135.565, 150.980, 156.415, 161.404, 180.175. IR νmax
049, 2925, 1681, 1593, 1569, 1481, 1336, 1301, 1134, 958
th ylth io-6-oxo-p yr im id in e. A suspension of resin 11 (500
mg, 1.20 mmol/g) in triethyl orthoformate (50 equiv, 5 mL)
was refluxed for 6 h. The isothiosemicarbazone (3 equiv) was
added and the mixture was refluxed for 12 h. The resin was
filtered and washed with 3 × 5 mL of EtOH, 3 × 5 mL with
-1
+
cm . MS m/z (rel intensity) 274 (M , 16), 244 (100), 230 (14),
41 (7.6), 132 (26), 112 (23), 77 (19). Elemental Anal. Calcd
for C14 OS: C 61.51; H 5.53; N 15.37. Found: C 61.46; H
.68; N 15.30.
-(N-P h en yleth yliden eam in o)-1,6-dih ydr o-2-m eth ylth io-
1
15 3
H N
CH
2
2 2
Cl , and thermally cyclized with an oil bath at 240 °C for
5
0 min under N atmosphere. The mixture was washed with
2
1
EtOH and acetone completely in the sintered glass funnel and
the filtrates were combined to afford the product by evapora-
tion.
1
6
(
7
-oxo-p yr im id in e (20g): White solid. Mp 76-78 °C. H NMR
CDCl
.46 (t, 2H, J ) 7.6 Hz), 7.53 (d, 1H, J ) 7.28 Hz), 7.80 (d, 1H,
3
) δ 2.25 (s, 3H), 2.52 (s, 3H), 6.30 (d, 1H, J ) 6.4 Hz),
1
3
1
-(N-Isop r op ylid en ea m in o)-1,6-d ih yd r o-2-m eth ylth io-
J ) 6.4 Hz), 8.01 (m, 2H). C NMR (CDCl ) δ 14.411, 17.185,
3
6
°
6
3
-oxo-p yr im id in e (20a ): Light yellow needles. Mp 158-160
110.169, 127.911, 128.660, 132.129, 135.602, 151.408, 156.946,
161.583, 177.847. IR νmax 3057, 2927, 1681, 1609, 1570, 1482,
1
C. H NMR (CDCl
3
) δ 1.86 (s, 3H), 2.30 (s, 3H), 2.48 (s, 3H),
-
1
+
.24 (d, 1H, J ) 6.4 Hz), 7.78 (d, 1H, J ) 6.4 Hz). IR νmax 3300,
1371, 1330, 1292, 1143 cm . MS m/z (rel intensity) 259 (M ,
198, 2926, 1698, 1634, 1482, 1360, 1184 cm-1
.
13
C NMR
10), 244 (100), 182 (13), 118 (48), 112 (44), 104 (20), 77 (67).
(
1
CDCl
3
) δ 14.337, 14.414, 20.226, 110.199, 151.460, 157.064,
Elemental Anal. Calcd for C13
16.20. Found: C 59.95; H 4.94; N 16.46.
13 3
H N OS:, C 60.21; H 5.05; N
+
60.294, 182.797. MS m/z (rel intensity) 197 (M , 16), 182
6
736 J . Org. Chem., Vol. 67, No. 19, 2002