PAPER
Synthesis and N- and O-Alkylation of 8-Azaxanthines
4173
3-Octyl-3H-[1,2,3]triazolo[4,5-d]pyrimidine-5,7(4H,6H)-dione
(2h)
Yield: 1.50 g (81%); mp 273–275 °C (EtOH); Rf = 0.47 (A).
IR (Nujol): 3210, 3050 (NH), 1725, 1700 cm–1 (CO).
UV (EtOH): lmax (log e) = 252 (4.10), 281 nm (3.90).
Anal. Calcd for C8H11N5O2: C, 45.93; H, 5.30; N, 33.48. Found: C,
45.62; H, 5.20; N, 33.47.
3-Isobutyl-6-methyl-3H-[1,2,3]triazolo[4,5-d]pyrimidine-
5,7(4H,6H)-dione (2n)
Yield: 1.11 g (71%); mp 241–243 °C (EtOH); Rf = 0.64 (A).
IR (Nujol): 3150 (NH), 1720, 1680 cm–1 (CO).
1H NMR (DMSO-d6): d = 0.85 (t, J = 7.2 Hz, 3 H, CH3), 1.15–1.38
(br s, 10 H, CH2[CH2]5CH3), 1.72–1.82 (m, 2 H, N-CH2CH2), 4.33
(t, J = 7.2 Hz, 2 H, N-CH2), 11.17 (s, 1 H, 6-NH), 12.31 (s, 1 H, 4-
NH).
UV (EtOH): lmax (log e) = 249 (4.12), 277 nm (3.86).
1H NMR (DMSO-d6): d = 0.88 (d, J = 6.6 Hz, 6 H, CH3CHCH3),
2.07–2.16 (m, 1 H, CH), 3.19 (s, 3 H, N-CH3), 4.20 (d, J = 7.2 Hz,
2 H, N-CH2), 12.63 (br s, 1 H, NH).
Anal. Calcd for C12H19N5O2: C, 54.32; H, 7.22; N, 26.40. Found: C,
54.34; H, 7.21; N, 26.19.
UV (EtOH): lmax (log e) = 252 (4.25), 282 nm (3.91).
3-Phenethyl-3H-[1,2,3]triazolo[4,5-d]pyrimidine-5,7(4H,6H)-
dione (2i)
Yield: 1.66 g (92%); mp 300–302 °C (MeOH); Rf = 0.37 (A).
Anal. Calcd for C9H13N5O2: C, 48.42; H, 5.87; N, 31.37. Found: C,
48.19; H, 5.77; N, 31.10.
IR (Nujol): 3170, 3070 (NH), 1735, 1700 cm–1 (CO).
3-Cyclopentyl-6-methyl-3H-[1,2,3]triazolo[4,5-d]pyrimidine-
5,7(4H,6H)-dione (2o)
Yield: 1.30 g (79%); mp 272–275 °C (EtOH); Rf = 0.62 (A).
IR (Nujol): 3170 (NH), 1750, 1670 cm–1 (CO).
1H NMR (DMSO-d6): d = 3.10 (t, J = 7.5 Hz, 2 H, Ph-CH2), 4.58 (t,
J = 7.5 Hz, 2 H, N-CH2), 7.17–7.30 (m, 5 H, Ph-H), 11.18 (s, 1 H,
6-NH), 12.31 (s, 1 H, 4-NH).
UV (EtOH): lmax (log e) = 250 (4.18), 280 (4.03).
1H NMR (DMSO-d6): d = 1.63–1.72 (m, 2 H, cyclopentyl-H), 1.78–
1.88 (m, 2 H, cyclopentyl-H), 1.97–2.15 (m, 4 H, cyclopentyl-H),
3.19 (s, 3 H, N-CH3), 4.86–4.98 (m, 1 H, N-CH), 12.61 (br s, 1 H,
NH).
Anal. Calcd for C12H11N5O2: C, 56.03; H, 4.31; N, 27.22. Found: C,
55.95; H, 4.36; N, 27.06.
3-o-Tolyl-3H-[1,2,3]triazolo[4,5-d]pyrimidine-5,7(4H,6H)-di-
one (2j)
Yield: 1.48 g (87%); mp 281–283 °C (EtOH); Rf = 0.40 (A).
IR (Nujol): 3170, 3050 (NH), 1730, 1700 cm–1 (CO).
UV (EtOH): lmax (log e) = 252 (4.14), 281 nm (3.95).
Anal. Calcd for C10H13N5O2: C, 51.06; H, 5.57; N, 29.77. Found: C,
50.94; H, 5.57; N, 29.82.
3-Cyclohexyl-6-methyl-3H-[1,2,3]triazolo[4,5-d]pyrimidine-
5,7(4H,6H)-dione (2p)
Yield: 1.24 g (71%); mp 294–296 °C (EtOH); Rf = 0.67 (A).
IR (Nujol): 3140 (NH), 1740, 1665 cm–1 (CO).
1H NMR (DMSO-d6): d = 1.25–1.49 (m, 3 H, Cy-H), 1.69–1.91 (m,
5 H, Cy-H), 2.0–2.04 (m, 2 H, Cy-H), 3.22 (s, 3 H, N-CH3), 4.40–
4.49 (m, 1 H, N-CH), 12.59 (br s, 1 H, NH).
1H NMR (DMSO-d6): d = 2.08 (s, 3 H, CH3), 7.41–7.54 (m, 4 H,
Ar-H), 11.28 (s, 1 H, 6-NH), 12.34 (s, 1 H, 4-NH).
UV (EtOH): lmax (log e) = 255 (4.23), 281 nm (3.97).
Anal. Calcd for C11H9N5O2: C, 54.32; H, 3.73; N, 28.79. Found: C,
54.50; H, 3.93; N, 28.49.
3-m-Tolyl-3H-[1,2,3]triazolo[4,5-d]pyrimidine-5,7(4H,6H)-di-
one (2k)
Yield: 1.41 g (83%); mp 295–297 °C (EtOH); Rf = 0.27 (A).
IR (Nujol): 3170, 3040 (NH), 1730, 1700 cm–1 (CO).
UV (EtOH): lmax (log e) = 252 (4.06), 281 nm (3.78).
Anal. Calcd for C11H15N5O2: C, 53.00; H, 6.07; N, 28.10. Found: C,
53.00; H, 6.05; N, 28.00.
1H NMR (DMSO-d6): d = 2.42 (s, 3 H, CH3), 7.39–7.45 (m, 4 H,
6-Methyl-3-octyl-3H-[1,2,3]triazolo[4,5-d]pyrimidine-
5,7(4H,6H)-dione (2q)
Yield: 1.78 g (91%); mp 182–184 °C (EtOAc); Rf = 0.68 (A).
Ar-H), 11.32 (s, 1 H, 6-NH), 12.38 (br s, 1 H, 4-NH).
UV (EtOH): lmax (log e) = 276 (4.18), 289 nm (4.18).
IR (Nujol): 3170 (NH), 1735, 1660 cm–1 (CO).
Anal. Calcd for C11H9N5O2: C, 54.32; H, 3.73; N, 28.79. Found: C,
54.30; H, 3.89; N, 28.54.
1H NMR (CDCl3): d = 0.86 (t, J = 6.6 Hz, 3 H, CH2CH3), 1.25–1.38
(m, 10 H, CH2[CH2]5CH3), 1.92–2.01 (m, 2 H, N-CH2CH2), 3.45 (s,
3 H, N-CH3), 4.46 (t, J = 7.2 Hz, 2 H, N-CH2), 12.29 (s, 1 H, NH).
3,6-Dimethyl-3H-[1,2,3]triazolo[4,5-d]pyrimidine-5,7(4H,6H)-
dione (2l)
Yield: 0.96 g (76%); mp 298 °C (dec., H2O) (Lit.10 296 °C);
UV (EtOH): lmax (log e) = 250 (4.08), 282 nm (3.92).
Rf = 0.35 (A).
Anal. Calcd for C13H21N5O2: C, 55.90; H, 7.58; N, 25.07. Found: C,
55.68; H, 7.36; N, 24.86.
1H NMR (DMSO-d6): d = 3.20 (s, 3 H, 6-N-CH3), 3.99 (s, 3 H, 3-N-
CH3), 12.69 (s, 1 H, NH).
6-Methyl-3-phenyl-3H-[1,2,3]triazolo[4,5-d]pyrimidine-
5,7(4H,6H)-dione (2r)
UV (EtOH): lmax (log e) = 252 (4.05), 278 nm (3.88).
Yield: 1.58 g (93%); mp 295–297 °C (EtOH); Rf = 0.51 (A).
IR (Nujol): 3220 (NH), 1735, 1685 cm–1 (CO).
3-Isopropyl-6-methyl-3H-[1,2,3]triazolo[4,5-d]pyrimidine-
5,7(4H,6H)-dione (2m)
Yield: 0.91 g (62%); mp 269–271 °C (EtOH); Rf = 0.61 (A).
IR (Nujol): 3170 (NH), 1730, 1665 cm–1 (CO).
1H NMR (DMSO-d6): d = 3.23 (s, 3 H, CH3), 7.61–7.65 (m, 5 H,
Ph-H), 12.75 (br s, 1 H, NH).
1H NMR (DMSO-d6): d = 1.52 (d, J = 6.6 Hz, 6 H, CH3CHCH3),
3.19 (s, 3 H, N-CH3), 4.81 (sept, J = 6.6 Hz, 1 H, CH), 12.57 (s, 1
H, NH).
UV (EtOH): lmax (log e) = 279 (4.23), 289 nm (4.26).
Anal. Calcd for C11H9N5O2: C, 54.32; H, 3.73; N, 28.79. Found: C,
54.09; H, 3.83; N, 29.11.
Synthesis 2006, No. 24, 4167–4179 © Thieme Stuttgart · New York