90
Y. Liang, H.-W. He, and Z.-W. Yang
Vol 48
Preparation of iminophosphorane 2. A solution of 1 (14.0
6-(4-Chlorophenyl)-5-di(i-propyl)amino-3-phenyl-2-thioxo-2,
3,6,7-tetrahydrothiazolo[4,5-d]pyrimidin-7-one (4e). Yellow
g, 0.05 mol) in CH3CN (150 mL) was added triphenylphos-
phine (26.5 g, 0.1 mol) and C2Cl6 (24.0 g, 0.1 mol). The mix-
ture was treated with triethylamine (28.0 mL, 0.2 mol), then
stirred for 4–5 h at 20ꢁC, the solution was condensed and the
residue was recrystallized from CH3CH2OH to give imino-
phosphorane 2 in yield 98.5%. Yellow crystal, m.p. 224.1–
1
crystals, m.p. > 270ꢁC. H NMR (400 MHz CDCl3) d (ppm):
0.85 (d, J ¼ 6.4 Hz, 12H, 4CH3), 3.47 (m, 2H, 2CH), 7.22–
7.60 (m, 9H, Ph-H); IR (KBr) t (cmꢀ1): 2981 (CAH), 1675
(C¼¼O), 1570, 1529 (Ph); Elemental Anal. Calcd. for
C23H23ClN4OS2 (471.0): C, 58.65; H, 4.92; N, 11.89; S, 13.61;
Found: C, 57.13; H, 4.87; N, 11.44; S, 13.24.
1
225.0ꢁC H NMR (400 MHz CDCl3): d (ppm): 7.50–7.27 (m,
6-(4-Chlorophenyl)-5-di(n-amyl)amino-3-phenyl-2-thioxo-2,3,
6,7-tetrahydrothiazolo[4,5-d]pyrimidin-7-one (4f). Yellow crys-
20H, Ph-H), 3.75 (q, 2H, J ¼ 6.8 Hz, ACH2), 0.97 (t, 3H, J ¼
7.2 Hz, ACH3); EI-MS (70 eV, m/z) (relative intensity %):
(m/z) 540 (Mþ, 100), 512(28), 262(99), 183(90), 107(54).
Preparation of carbodiimides 3. To a solution of imino-
phosphorane 2 (0.54 g, 1 mmol) in anhyd CH2Cl2 (10 mL)
was added aromatic isocyanate (1.1 mmol) under N2 at r.t. Af-
ter the reaction mixture was left unstirred for 5–12 h, the sol-
vent was removed off under reduced pressure and Et2O/petro-
leum ether was added to precipitate triphenylphosphine oxide.
Removal of the solvent gave carbodiimides 3, which were
used directly without further purification partly because they
easily decomposed.
1
tals, m.p. 177.2–178.7ꢁC. H NMR (400 MHz CDCl3) d (ppm):
0.79–0.86 (m, 10H, 2CH2CH3), 1.08–1.14 (m, 8H, 2CH2CH2),
2.83 (t, J ¼ 8.0 Hz, 4H, 2CH2), 7.22–7.57 (m, 9H, Ph-H); IR
(KBr) t (cmꢀ1): 2957(CAH), 1682 (C¼¼O), 1571, 1532(Ph);
Elemental Anal. Calcd. for C27H31ClN4OS2 (527.1): C, 61.52;
H, 5.93; N, 10.63; S, 12.17; Found: C, 60.77; H, 5.85; N,
10.84; S, 11.84.
5-Diethylamino-6-(4-fluorophenyl)-3-phenyl-2-thioxo-2,3,6,
7-tetrahydrothiazolo[4,5-d]pyrimidin-7-one (4g). Yellow crys-
1
tals, m.p. 219.5–220.4ꢁC. H NMR(400 MHz CDCl3) d (ppm):
General procedure for the preparation of compounds
4a–4p. To the solution of carbodiimides 3 prepared above in
ethanol (15 mL) was added alkylamine (1.1 mmol) and a cata-
lytic amount of sodium ethoxide in ethanol. After the mixture
had been stirred for 2–3 h at 303 K, the solution was concen-
trated and the residue was recrystallized from CH3CN to give
0.72 (t, J ¼ 7.2 Hz, 6H, 2CH3), 2.95 (q, J ¼ 7.2 Hz, 4H,
2CH2), 7.20–7.57 (m, 9H, Ph-H); IR (KBr) t (cmꢀ1): 2976
(CAH), 1684 (C¼¼O), 1571, 1526(Ph); Elemental Anal. Calcd.
for C21H19FN4OS2 (426.5): C, 59.13; H, 4.49; N, 13.14; S,
15.04; Found: C, 59.28; H, 4.91; N, 12.79; S, 15.51 .
5-Di(i-propyl)amino-6-(4-fluorophenyl)-3-phenyl-2-thioxo-2,
3,6,7-tetrahydrothiazolo[4,5-d]pyrimidin-7-one (4h). Yellow
crystals, m.p. 265.1–265.4ꢁC. 1H NMR(400 MHz CDCl3) d
(ppm): 0.85 (d, J ¼ 6.8 Hz, 12H, 4CH3), 3.47 (m, 2H, 2CH),
7.15–7.60 (m, 9H, Ph-H); IR (KBr) t (cmꢀ1): 2977 (CAH),
1679 (C¼¼O), 1573, 1529(Ph); Elemental Anal. Calcd. for
C23H23FN4OS2 (454.6): C, 60.77; H, 5.10; N, 13232; S, 14.11;
Found: C, 60.43; H, 4.81; N, 12.85; S, 14.54.
5-Di(n-amyl)amino-6-(4-fluorophenyl)-3-phenyl-2-thioxo-2,
3,6,7-tetra hydrothiazolo[4,5-d]pyrimidin-7-one (4i). Yellow
crystals, m.p. 153.5–154.1ꢁC. 1H NMR(400 MHz CDCl3) d
(ppm): 0.79–0.87 (m, 10H, 2CH2CH3), 1.08–1.13 (m, 8H,
2CH2CH2), 2.83 (t, J ¼ 8.0 Hz, 4H, 2CH2), 7.19–7.56 (m, 9H,
Ph-H); IR (KBr) t (cmꢀ1): 2958 (CAH), 1681 (C¼¼O), 1572,
1532(Ph); Elemental Anal. Calcd. for C27H31FN4OS2 (510.7):
C, 63.50; H, 6.12; N, 10.97; S, 12.56; Found: C, 63.45; H,
6.65; N, 10.46; S, 12.91.
5-Diethylamino-3-(4-fluorophenyl)-6-phenyl-2-thioxo-2,
3,6,7-tetrahydrothiazolo[4,5-d]pyrimidin-7-one (4j). Yellow
crystals, m.p. 172.6–173.2ꢁC. 1H NMR (400 MHz CDCl3)
d (ppm): 0.71 (t, J ¼ 7.2 Hz, 6H, 2CH3), 2.96 (q, J ¼ 7.2 Hz, 4H,
2CH2), 7.25–7.50 (m, 9H, Ph-H); IR (KBr) t (cmꢀ1): 2976
(CAH), 1689 (C¼¼O), 1573, 1528(Ph); Elemental Anal. Calcd. for
C21H19FN4OS2 (426.5): C, 59.13; H, 4.49; N, 13.14; S, 15.04;
Found: C, 59.36; H, 4.58; N, 12.89; S, 15.59.
pure
5-alkylamino-3,6-diaryl-2-thioxo-2,3,6,7-tetrahydrothia-
zolo[4,5-d]pyrimidin-7-ones 4a–4p.
5-Diethylamino-3,6-diphenyl-2-thioxo-2,3,6,7-tetrahydro-
thiazolo[4,5-d]pyrimidin-7-one (4a). Yellow crystals, m.p.
1
206.2–207.1ꢁC. H NMR(400 MHz CDCl3) d (ppm): 0.68 (t, J
¼ 7.2 Hz, 6H, 2CH3), 3.09 (q, J ¼ 7.2 Hz, 4H, 2CH2), 7.28–
7.59 (m, 10H, Ph-H); IR (KBr) t (cmꢀ1): 2974 (CAH), 1687
(C¼¼O), 1573, 1528(Ph); Elemental Anal. Calcd. for
C21H20N4OS2 (408.5): C, 61.74; H, 4.93; N, 13.71; S, 15.70;
Found: C, 61.31; H, 5.01; N, 13.50; S, 15.23.
5-Di(i-propyl)amino-3,6-diphenyl-2-thioxo-2,3,6,7-tetrahydro-
thiazolo[4,5-d]pyrimidin-7-one (4b). Yellow crystals, m.p.
1
254.1–255.6ꢁC. H NMR(400 MHz CDCl3) d (ppm): 0.82 (d, J
¼ 6.4 Hz, 12H, 4CH3), 3.49 (m, 2H, 2CH), 7.25–7.58 (m, 10H,
Ph-H); IR (KBr) t (cmꢀ1): 2962 (CAH), 1689 (C¼¼O), 1571,
1525 (Ph); Elemental Anal. Calcd. for C23H24N4OS2 (436.6):
C, 63.27; H, 5.54; N, 12.83; S, 14.69; Found: C, 63.37; H,
5.33; N, 12.69; S, 14.15.
5-Di(n-amyl)amino-3,6-diphenyl-2-thioxo-2,3,6,7-tetrahydro-
thiazolo[4,5-d]pyrimidin-7-one (4c). Yellow crystals, m.p.
151.1–151.7ꢁC. 1H NMR(400 MHz CDCl3) d (ppm): 0.77–
0.85 (m, 10H, 2CH2CH3), 1.06–1.10 (m, 8H, 2CH2CH2), 2.82
(t, J ¼ 8.0 Hz, 4H, 2CH2), 7.29–7.57 (m, 10H, Ph-H); IR
(KBr) t (cmꢀ1): 2953 (CAH), 1684 (C¼¼O), 1573, 1530(Ph);
Elemental Anal. Calcd. for C27H32N4OS2 (492.7): C, 65.22; H,
6.55; N, 11.37; S, 13.02; Found: C, 65.73; H, 6.50; N, 11.26;
S, 12.53.
5-Di(i-butyl)amino-3-(4-fluorophenyl)-6-phenyl-2-thioxo-2,
3,6,7-tetra hydrothiazolo[4,5-d]pyrimidin-7-one (4k). Yellow
crystals, m.p. 193.6–195.1ꢁC. 1H NMR (400 MHz CDCl3) d
(ppm): 0.67 (d, J ¼ 6.4 Hz, 12H, 4CH3), 1.62–1.73 (m, 2H,
2CH), 7.25–7.51 (m, 9H, Ph-H); IR (KBr) t (cmꢀ1): 2964
(CAH), 1681 (C¼¼O), 1574, 1529(Ph); Elemental Anal. Calcd.
for C25H27FN4OS2 (482.6): C, 62.21; H, 5.64; N, 11.61; S,
13.29; Found: C, 62.58; H, 5.87; N, 12.03; S, 13.57.
6-(4-Chlorophenyl)-5-diethylamino-3-phenyl-2-thioxo-2,3,6,
7-tetrahydrothiazolo[4,5-d]pyrimidin-7-one (4d). Yellow crys-
1
tals, m.p. 246.1–247.3ꢁC. H NMR(400 MHz CDCl3) d (ppm):
0.73 (t, J ¼ 7.2 Hz, 6H, 2CH3), 2.95 (q, J ¼ 7.2 Hz, 4H,
2CH2), 7.24–7.57 (m, 9H, Ph-H); IR (KBr) t (cmꢀ1): 2965
(CAH), 1683 (C¼¼O), 1572, 1525(Ph); Elemental Anal. Calcd.
for C21H19ClN4OS2 (443.0): C, 56.94; H, 4.32; N, 12.65; S,
14.48; Found: C, 56.28; H, 4.31; N, 12.38; S, 14.15.
5-Di(n-amyl)amino-3-(4-fluorophenyl)-6-phenyl-2-thioxo-2,
3,6,7-tetra hydrothiazolo[4,5-d]pyrimidin-7-one (4l). Yellow
crystals, m.p. 173.6–174.2ꢁC. 1H NMR (400 MHz CDCl3) d
Journal of Heterocyclic Chemistry
DOI 10.1002/jhet