562
HETEROCYCLES, Vol. 75, No. 3, 2008
2. 2-Ethoxy-7-methyl-6-oxo-1,6-dihydropurine (2b) (1.89g, 97%); mp 214-215 oC (EtOH-water).
1H NMR (DMSO-d6) δ: 1.29 (t, J = 6.9 Hz, 3H, Me), 3.88 (s, 3H, NMe), 4.30 (q, J = 6.9 Hz, 2H, OCH2),
7.92 (s, 1H, C8), 10.02 (s, 1H, NH), EI MS m/z: 194 (M+, 76), 166 (M-C2H4, 100). Anal. Calcd for
C8H10N4O2: C 49.48, H 5.19, N 28.85. Found C 49.18, H 5.25, N 28.54.
3. 2-Allyloxy-7-methyl-6-oxo-1,6-dihydropurine (2c) (1.95g, 95%); mp 199-200 oC (EtOH-water).
1H NMR (DMSO-d6) δ: 3.89 (s, 3H, NMe), 4.80 (d, J = 6.4 Hz, 2H, OCH2), 5.25 (d, J = 11.1 Hz, 1H,
=CH2), 5.40 (d, J = 18.0 Hz, 1H, =CH2), 6.04 (m, 1H, =CH), 7.94 (s, 1H, H8), 10.04 (s, 1H, NH), EI MS
m/z: 206 (M+, 23), 165 (M-C3H5, 100). Anal. Calcd for C9H10N4O2: C 52.42, H 4.89, N 27.17. Found C
52.18, H 4.96, N 26.88.
4. 2-Benzyloxy-7-methyl-6-oxo-1,6-dihydropurine (2d) (method A: 0.54g, 21%, method B: 2.41g, 94%);
mp 191-192 oC (EtOH).
1H NMR (DMSO-d6) δ: 3.87 (s, 3H, NMe), 5.32 (s, 2H, CH2) 7.32 (t, J = 7.4 Hz, 1H, p-C6H5), 7.38 (t, J =
7.4 Hz, 2H, m-C6H5), 7.44 (d, J = 7.4 Hz, 2H, o-C6H5), 7.89 (s, 1H, H8), 10.12 (s, 1H, NH), EI MS m/z:
+
256 (M+, 30), 165 (M-CH2C6H5, 13), C6H5CH2 (100). Anal. Calcd for C13H12N4O2: C 60.93, H 4.72, N
21.86. Found C 60.81, H 4.77, N 21.49.
o
5. 2-Methylthio-7-methyl-6-oxo-1,6-dihydropurine (2e) (1.92g, 98%); mp 303-305 C (water), lit.,10b mp
> 300 oC.
6. 2-Ethylthio-7-methyl-6-oxo-1,6-dihydropurine (2f) (1.89g, 90%); mp 275-276 oC (EtOH-water).
1H NMR (DMSO-d6) δ: 1.27 (t, J = 7.2 Hz, 3H, Me), 3.03 (q, J = 7.2 Hz, 2H, CH2), 3.88 (s, 3H, NMe),
7.82 (s, 1H, H8), 10.19 (s, 1H, NH), EI MS m/z: 210 (M+, 100), 182 (M-C2H4, 43). Anal. Calcd for
C8H10N4OS: C 45.70, H 4.79, N 26.65. Found C 45.49, H 4.69, N 26.39.
7. 2-Allylthio-7-methyl-6-oxo-1,6-dihydropurine (2g) (method A: 0.42 g, 19%, method B: 1.05g, 88%);
mp 216-218 oC (EtOH-water).
1H NMR (DMSO-d6) δ: 3.83 (d, J = 6.9 Hz, 2H, SCH2), 3.91 (s, 3H, NMe), 5.12 (d, J = 10.5 Hz, 1H,
=CH2), 5.31 (d, J = 17.4 Hz, 1H, =CH2), 5.95 (m, 1H, =CH), 8.07 (s, 1H, H8), 10.38 (s, 1H, NH), EI MS
m/z: 222 (M+, 100), 181 (M-C3H5, 55). Anal. Calcd for C9H10N4OS: C 48.64, H 4.53, N 25.21. Found C
48.41, H 4.55, N 24.92.
In the case of method B an additional product was isolated: 2-allylthio-6-ethoxy-7-methylpurine (1i)
(0,20g, 8%); mp 165-166 oC (EtOH).
1H NMR (CDCl3) δ: 1.47 (t, J = 7.2 Hz, 3H, Me), 3.90 (d, J = 6.9 Hz, 2H, SCH2), 4.02 (s, 3H, NMe),
4.60 (q, J = 7.2 Hz, 2H, OCH2), 5.11 (d, J = 10.2 Hz, 1H, =CH2), 5.34 (d, J = 17.3 Hz, 1H, =CH2), 6.04
(m, 1H, =CH), 8.03 (s, 1H, H8), EI MS m/z: 250 (M+, 39), 209 (M-C3H5, 65), 222 (M-C2H4, 100). Anal.
Calcd for C11H14N4OS: C 52.78, H 5.64, N 22.38. Found C 52.52, H 5.74, N 22.09.