5326
L.-K. Huang et al. / Tetrahedron 63 (2007) 5323–5327
230.1160. Anal. Calcd for C12H14N4O: C, 62.59; H, 6.13; N,
24.33. Found: C, 62.20; H, 6.13; N, 23.90.
3.2.12. 6-Ethoxypurine.5 White solid, mp 220–222 ꢀC (lit.
1
223–224 ꢀC); H NMR (300 MHz, DMSO-d6) d 13.38 (s,
1H, 9-NH), 8.46 (s, 1H), 8.35 (s, 1H), 4.57 (q, J¼7.2 Hz,
3.2.3. 5-Morpholinocytosine. Pale yellow solid, mp 245 ꢀC
2H), 1.40 (t, J¼7.2 Hz, 3H).
1
(dec); IR (KBr) 3455, 1651, 1454, 1230 cmꢁ1; H NMR
(300 MHz, DMSO-d6) d 10.23 (br, 1H, 1-NH), 7.13 (s, 2H,
–NH2), 6.56 (s, 1H, 6-H), 3.66 (t, J¼4.5 Hz, 4H), 2.65 (t,
J¼4.5 Hz, 4H); 13C NMR (75 MHz, DMSO-d6) d 163.7,
155.5, 132.8, 119.8, 66.3 (2C), 52.0 (2C); MS m/e 196
(M+), 180, 111, 86; HRMS m/e calcd for 196.1284, found
196.0968. Anal. Calcd for C8H12N4O2: C, 48.97; H, 6.16;
N, 28.56. Found: C, 49.09; H, 6.25; N, 28.05.
3.2.13. 6-Benzyloxypurine.6 Light brown solid, mp 173–
1
175 ꢀC (lit. 171–172 ꢀC); H NMR (300 MHz, DMSO-d6)
d 13.44 (s, 1H, 9-NH), 8.51 (s, 1H), 8.35 (s, 1H), 7.53–
7.32 (m, 5H, Ph), 5.61 (s, 2H, OCH2Ph).
3.2.14. 6-Phenoxypurine.7 White solid, mp 213–216 ꢀC
1
(lit. 217–218 ꢀC); H NMR (300 MHz, DMSO-d6) d 13.56
(s, 1H, 9-NH), 8.50 (s, 1H), 8.41 (s, 1H), 7.49–7.27 (m,
5H, OPh).
3.2.4. 5-Piperidylcytosine. Pale yellow solid, mp 290 ꢀC
1
(dec); IR (KBr) 3465, 1649, 1453, 1226 cmꢁ1; H NMR
(300 MHz, DMSO-d6) d 10.11 (br, 1H, 1-NH), 7.04 (s, 2H,
–NH2), 6.33 (s, 1H, 6-H), 2.60 (m, 4H), 1.59 (m, 4H), 1.44
(m, 2H); 13C NMR (75 MHz, DMSO-d6) d 163.9, 160.0,
155.5, 132.2, 121.0, 53.0 (2C), 25.8 (2C), 23.5; MS m/e
194 (M+), 177, 110, 84; HRMS m/e calcd for 194.2376,
found 194.1163. Anal. Calcd for C9H14N4O: C, 55.65; H,
7.27; N, 28.85. Found: C, 55.54; H, 7.02; N, 28.70.
3.2.15. 6-Methylthiopurine.7 White solid, mp 222–224 ꢀC
1
(lit. 220–223 ꢀC); H NMR (300 MHz, DMSO-d6) d 8.69
(s, 1H), 8.41 (s, 1H), 2.88 (s, 3H, SCH3).
3.2.16. 6-Phenylthiopurine. White solid, mp 261–262 ꢀC;
1
IR (KBr) 3085, 1240 cmꢁ1; H NMR (300 MHz, DMSO-
d6) d 13.56 (s, 1H, 9-NH), 8.53 (s, 1H), 8.50 (s, 1H), 7.51–
7.48 (m, 5H, SPh); 13C NMR (75 MHz, DMSO-d6)
d 165.9, 155.9, 151.2, 136.6, 136.4, 129.1 (4C), 126.2,
125.9; MS m/e 228 (M+), 119, 109, 77; HRMS m/e calcd
for 228.2710, found 228.0475. Anal. Calcd for C11H8N4S:
C, 57.88; H, 3.53; N, 24.54. Found: C, 57.59; H, 4.05; N,
24.60.
3.2.5. 5-Phenylthiocytosine. Colourless solid, mp 308 ꢀC
1
(dec); IR (KBr) 3447, 1684, 1456, 1235 cmꢁ1; H NMR
(300 MHz, DMSO-d6) d 11.00 (s, 1H, NH), 7.84 (s, 1H,
4-NH), 7.50 (s, 1H, 4-NH), 7.33–7.15 (m, 5H, SPh), 6.78
(s, 2H, –NH2); 13C NMR (75 MHz, DMSO-d6) d 163.3,
160.0, 153.3, 135.4, 129.0 (2C), 128.2 (3C), 88.7, 58.1,
39.4, 33.4, 27.9; MS m/e 219 (M+), 142, 110, 77; HRMS
m/e calcd for 219.2262, found 219.0459. Anal. Calcd for
C10H9N3OS: C, 41.60; H, 4.07; N, 8.09; S, 18.50. Found:
C, 41.70; H, 4.15; N, 8.11; S, 18.60.
3.2.17. 6-Phenylselenylpurine. Pale yellow solid, mp 240–
1
242 ꢀC; IR (KBr) 3078, 1227 cmꢁ1; H NMR (300 MHz,
DMSO-d6) d 13.59 (s, 1H, 9-NH), 8.53 (s, 1H), 8.51 (s,
1H), 7.71–7.43 (m, 5H, SePh); 13C NMR (75 MHz,
DMSO-d6) d 155.9, 151.7, 150.2, 144.3, 136.3, 131.6
(4C), 129.4, 129.0, 124.8; MS m/e 276 (M+), 157, 119, 77;
HRMS m/e calcd for 275.9914, found 275.9921. Anal. Calcd
for C11H8N4Se: C, 48.01; H, 2.93; N, 20.36. Found: C,
48.27; H, 2.82; N, 20.16.
3.2.6. 6-Benzylaminopurine.2 Pale yellow solid, mp 237–
1
238 ꢀC (lit. 236–237 ꢀC); H NMR (300 MHz, DMSO-d6)
d 12.79 (s, 1H, NH), 8.36 (s, 1H, 2-H), 8.10 (s, 1H, 8-H),
7.46–7.17 (m, 5H, Ph), 4.76 (br, 2H, –CH2Ph).
3.2.7. 6-Butylaminopurine.2 White solid, mp 230–232 ꢀC
3.2.18. 2-Amino-6-benzylaminopurine.1a White solid, mp
247–248 ꢀC (lit. 228–230 ꢀC); 1H NMR (300 MHz, DMSO-
d6) d 12.06 (s, 1H, 9-NH), 7.63 (s, 1H, 8-H), 7.34–7.16 (m,
5H, Ph), 5.67 (s, 2H, –NH2), 4.64 (br, 2H, –NCH2Ph).
1
(lit. 223–234 ꢀC); H NMR (300 MHz, DMSO-d6) d 12.84
(s, 1H, 9-NH), 8.14 (s, 1H, 2-H), 8.05 (s, 1H, 8-H), 3.46
(br, 2H), 1.61–1.49 (m, 2H), 1.38–1.26 (m, 2H), 0.88 (t,
J¼7.2 Hz, 3H).
3.2.19. 2-Amino-6-butylaminopurine.1b White solid, mp
3.2.8. 6-Anilinopurine.2 Pale yellow solid, mp 290–291 ꢀC
181–182 ꢀC; H NMR (300 MHz, DMSO-d6) d 11.99 (br,
1
1
(lit. 284–286 ꢀC); H NMR (300 MHz, DMSO-d6) d 13.15
1H, 9-NH), 7.62 (s, 1H, 8-H), 6.97 (br, 1H, NH), 5.60 (s,
2H, –NH2), 3.42 (m, 2H), 1.58–1.48 (m, 2H), 1.38–1.25
(m, 2H), 0.89 (t, J¼7.2 Hz, 3H).
(s, 1H, 9-NH), 9.74 (s, 1H, NHPh), 8.37 (s, 1H), 8.22 (s,
1H), 7.93–6.99 (m, 5H, Ph).
3.2.9. 6-Morpholinopurine.2 White solid, mp 315–316 ꢀC
3.2.20. 2-Amino-6-cyclohexylaminopurine.1c Pale yellow
solid, mp 204–205 ꢀC; 1H NMR (300 MHz, DMSO-d6)
d 12.00 (s, 1H, 9-NH), 7.61 (s, 1H, 8-H), 6.70 (d,
J¼8.1 Hz, 1H, NH), 5.60 (s, 2H, –NH2), 4.06 (m, 1H),
1.82–1.12 (m, 10H).
1
(lit. 300–301 ꢀC); H NMR (300 MHz, DMSO-d6) d 13.00
(br, 1H, 9-NH), 8.22 (s, 1H, 2-H), 8.13 (s, 1H, 8-H), 4.19
(m, 4H), 3.70 (m, 4H).
3.2.10. 6-Piperidylpurine.2 White solid, mp 286–287 ꢀC
1
(lit. 274–275 ꢀC); H NMR (300 MHz, DMSO-d6) d 12.89
3.2.21. 2-Amino-6-anilinopurine.1d Pale yellow solid, mp
1
(br, 1H, 9-NH), 8.18 (s, 1H, 2-H), 8.07 (s, 1H, 8-H), 4.18
(m, 4H), 1.66–1.63 (m, 2H), 1.57–1.48 (m, 4H).
330–331 ꢀC; H NMR (300 MHz, DMSO-d6) d 13.10 (br,
1H, 9-NH), 10.61 (br, 1H, NHPh), 8.17 (s, 1H, 8-H), 7.99–
7.08 (m, 5H, Ph).
3.2.11. 6-Methoxypurine.4 White solid, mp 195–196 ꢀC
1
(lit. 197–199 ꢀC); H NMR (300 MHz, DMSO-d6) d 8.49
(s, 1H), 8.36 (s, 1H), 4.07 (s, 3H, OCH3).
3.2.22. 2-Amino-6-morpholinopurine.1e White solid, mp
1
274–275 ꢀC; H NMR (300 MHz, DMSO-d6) d 12.18 (br,