5592
Z. Hasnı´k et al. / Tetrahedron Letters 48 (2007) 5589–5592
9. Kucharˇ, M.; Pohl, R.; Votruba, I.; Hocek, M. Eur. J. Org.
(40 ml) and extracted with chloroform (3 · 30 ml). The
combined organic layers were dried over MgSO4, filtered
and the solvent was evaporated. The residue was
chromatographed on a silica gel column (ethyl acetate/
hexane) to give 3a (91%). Yellowish crystals (CH2Cl2/
heptane), mp 90–96 ꢁC. MS (FAB): 297 (100, M+1).
HRMS (FAB): for C16H17N4O2 (M + H+) calculated
Chem. 2006, 5083–5098.
10. Reviews: (a) Hocek, M. Eur. J. Org. Chem. 2003, 245–254;
(b) Agrofoglio, L. A.; Gillaizeau, I.; Saito, Y. Chem. Rev.
2003, 103, 1875–1916; (c) Lakshman, M. K. J. Organomet.
Chem. 2002, 653, 234–251.
ˇ
11. (a) Capek, P.; Pohl, R.; Hocek, M. J. Org. Chem. 2004, 69,
1
ˇ
7985–7988; (b) Capek, P.; Pohl, R.; Hocek, M. J. Org.
297.1351, found 297.1356. H NMR (400 MHz, CDCl3):
Chem. 2005, 70, 8001–8008.
1.27 (t, 3 H, J = 7.1); 4.22 (q, 2H, J = 7.1); 4.26 (s, 2H);
5.45 (s, 2H); 7.29–7.41 (m, 5H); 8.04 (s, 1H); 8.97 (s, 1H).
13C NMR (100.6 MHz, CDCl3): 14.11, 39.03, 47.37, 61.36,
127.92, 128.66, 129.16, 133.00, 134.93, 144.33, 151.32,
152.62, 154.55, 169.21. IR, mmax: 2983, 1744, 1599, 1500,
1407, 1333, 1178 cmꢀ1. Anal. Calcd for C16H16N4O2: C,
64.85; H, 5.44; N, 18.91. Found: C, 64.46; H. 5.37; N
18.50.
12. (a) Øveras, A. T.; Bakkestuen, A. K.; Gundersen, L.-L.;
Rise, F. Acta Chem. Scand. 1997, 51, 1116–1124; (b)
Wang, J.-F.; Zhang, L.-R.; Yang, Z.-J.; Zhang, L.-H.
Bioorg. Med. Chem. 2004, 12, 1425–1429.
13. Montgomery, J. A.; Hewson, K. J. Org. Chem. 1965, 30,
1528–1532.
14. Odijk, W. M.; Koomen, G. J. Tetrahedron 1985, 41, 1893–
1904.
15. (a) Sakata, S.; Yonei, S.; Yoshino, H. Chem. Pharm. Bull.
1982, 30, 2583–2585; (b) Hamamichi, N.; Miyasaka, T. J.
Heterocycl. Chem. 1990, 27, 2011–2015.
20. NaBH4 (380 mg, 10 mmol) was added to a stirred solution
of a purine 3a (296 mg, 1 mmol) in EtOH (8 ml), the
reaction was stirred at rt for 12 h and then quenched by
MeOH (8 ml) and 1 M NH4Cl (10 ml). The solvents were
evaporated and the residue extracted with chloroform
(3 · 30 ml). The combined organic layers were dried over
MgSO4, filtered and the solvent evaporated. The residue
was dissolved in CH2Cl2 (10 ml) and MnO2 (174 mg,
2 mmol) was added. The mixture was sonicated at rt for
1 h, then filtered through Celite and the solvent evapo-
rated. The residue was chromatographed on a silica gel
column (chloroform/methanol) to give 4a (82%). White
crystals, mp 72–73 ꢁC (CH2Cl2/heptane). MS (FAB): 255
(100, M+1), 91 (55). HRMS (FAB): for C14H15N4O
16. Fauvarque, J. F.; Jutand, A. J. Organomet. Chem. 1979,
177, 273–281.
17. (a) Sorensen, M.; Lee, S.; Liu, X.; Wolkowski, J. P.;
Hartwig, J. F. J. Am. Chem. Soc. 2002, 124, 12557–12565;
(b) Hama, T.; Liu, X.; Culkin, D. A.; Hartwig, J. F. J. Am.
Chem. Soc. 2003, 125, 11176–11177; (c) Hama, T.; Culkin,
D. A.; Hartwig, J. F. J. Am. Chem. Soc. 2006, 128, 4976–
4985; (d) Hlavinka, M. L.; Hagadorn, J. R. Tetrahedron
Lett. 2006, 47, 5049–5053.
18. Knochel, P.; Yeh, M. C. P.; Berk, S. C.; Talbert, J. J. Org.
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1
(M+H+) calculated 255.1246, found 255.1242. H NMR
19. A solution of ethyl bromoacetate (417.5 mg, 278.33 ll,
2.5 mmol) in 3 ml of THF was added at rt to an argon-
purged flask containing a suspension of zinc dust (327 mg,
5 mmol) preactivated with TMSCl (15 ll) in THF (2 ml).
The suspension was stirred for 1 h, then the zinc was
allowed to settle and 4 ml of the supernatant (4 ml) was
transferred through a septum to a mixture of 2a (122 mg,
0.5 mmol), Pd2dba3 (8 mg, 0.01 mmol) and bpdbp (12 mg,
0.04 mmol) in THF (1 ml) under Ar. The mixture was
stirred for 12 h and then quenched with 1 M NH4Cl
(400 MHz, CDCl3): 3.45 (t, 2H, J = 5.4,); 4.16 (bt, 2H,
J = 5.4); 4.89 (bs, 1H); 5.45 (s, 2H); 7.28–7.40 (m, 5H);
8.04 (s, 1H); 8.90 (s, 1H). 13C NMR (100.6 MHz, CDCl3):
36.04, 47.25, 60.19, 127.81, 128.58, 129.08, 132.15, 134.85,
143.71, 150.70, 152.23, 161.14. IR, mmax: 2931, 1596, 1500,
1407, 1331, 1196, 1063 cmꢀ1. Anal. Calcd for C14H14N4O:
C, 66.13; H, 5.55; N, 22.03. Found: C, 65.87; H, 5.47; N,
21.90.
21. Hocek, M.; Holy´, A. Collect. Czech. Chem. Commun.
1995, 60, 1386–1389.