8
Helvetica Chimica Acta Vol. 86 (2003)
(d, Me2CH). Anal. calc. for C18H18N6O4 ¥ 0.5 H2O (391.4): C 55.24, H 4.89, N 21.47; found: C 55.38, H 5.00, N
21.40.
9. N-{6-Methyl-4-[2-(4-nitrophenyl)ethoxy]pteridin-2-yl}acetamide (24). As described in Exper. 7.1 with N2-
acetyl-6-methylpterin (5; 0.219 g, 1 mmol): 0.17 mg (46%) of 24. Colorless crystals. M.p. 217 2188 (AcOEt/
MeOH 1:1). Rf (CHCl3/MeOH 9 :1) 0.51. 1H-NMR (CDCl3): 8.91 (d, HÀC(7)); 8.21 (d, 2 Ho to NO2); 8.18 (br.
s, NH); 7.55 (d, 2 Hm to NO2); 4.90( t, OCH2CH2); 3.42 (t, OCH2CH2); 2.81 (s, MeÀC(6)); 2.68 (s, Ac). Anal.
calc. for C17H16N6O4 (368.4): C 55.43, H 4.38, N 22.81; found: C 55.07, H 4.42, N 22.80.
10. N-{6-Methyl-4-[2-(4-nitrophenyl)ethoxy]pteridin-2-yl}isobutyramide (25). As described in Exper. 7.1,
with N2-isobutyryl-6-methylpterin (6; 0.248 g, 1 mmol): 0.17 mg (48%) of 25. Colorless crystals. M.p. 200 2028
(dec.). Rf (CHCl3/MeOH 9 :1) 0.69. 1H-NMR (CDCl3): 8.90( d, HÀC(7)); 8.21 (d, 2 Ho NO2); 8.07 (br. s, NH);
7.58 (d, 2 Hm to NO2); 4.95 (t, OCH2CH2); 3.42 (t, OCH2CH2); 3.21 (sept., Me2CH); 2.80( s, Ac); 1.30
(d, Me2CH). Anal. calc. for C19H20N6O4 ¥ 0.5 H2O (405.4): C 56.29, H 5.21, N 20.92; found: C 56.31, H 5.12, N
20.52.
11. N-{[(Acetyloxy)methyl]-4-[2-(4-nitrophenyl)ethoxy]pteridin-2-yl}acetamide (26). As described in
Exper. 7.1, with 8 (0.28 g, 1 mmol): 0.308 g (70%) of 26. Colorless crystals. M.p. 175 1778. Rf (CHCl3/MeOH
9 :1) 0.45. 1H-NMR (CDCl3): 9.06 (d, HÀC(7)); 8.17 (d, 2 Ho to NO2); 8.03 (br. s, NH); 7.53 (d, 2 Hm to NO2);
5.40( s, CH2ÀC(6)); 4.85 (t, OCH2CH2); 3.37 (t, OCH2CH2); 2.66 (s, AcN); 2.18 (s, AcO). Anal. calc. for
C19H18N6O6 ¥ 0.5 H2O (435.4): C 52.58, H 4.40, N 19.30; found: C 52.58, H 4.43, N 19.21.
12. N-{6-[(Isobutyryloxy)methyl]-4-[2-(4-nitrophenyl)ethoxy]pteridin-2-yl}isobutyramide (27). As de-
scribed in Exper. 7.1, with 9 (0.336 g, 1 mmol): 0.2 g (41%) of 27. Colorless crystals. M.p. 137 1388. Rf
(CHCl3/MeOH 9 :1) 0.73. 1H-NMR (CDCl3): 9.07 (d, HÀC(7)); 8.18 (d, 2 Ho to NO2); 8.14 (br. s, NH); 7.56
(d, 2 m to NO2); 5.44 (t, CH2ÀC(6)); 4.94 (t, OCH2CH2); 3.37 (t, OCH2CH2); 3.22 (sept., 1 Me2CH); 2.71
(s, 1 Me2CH); 1.31 (d, 1 Me2CH); 1.25 (d, 1 Me2CH) . Anal. calc. for C23H26N6O6 (482.5): C 57.25, H 5.43, N
17.42; found: C 56.83, H 5.47, N 16.96.
13. N-{4-[2-(4-Nitrophenyl)ethoxy]-6-phenylpteridin-2-yl}acetamide (28). As described in Exper. 7.1, with
11 (0.282 g, 1 mmol): 0.29 g (68%) of 28. Colorless crystals. M.p. 242 2448. Rf (CHCl3/MeOH 9 :1) 0.66.
1H-NMR (CDCl3): 9.48 (d, HÀC(7)); 8.22 (d, 2 Ho to NO2); 8.17 (d, 2 arom. H); 8.12 (br. s, 1 NH); 7.62 (d, 2 Hm
to NO2); 7.62 7.47 (m, 3 arom. H); 4.88 (t, OCH2CH2); 3.41 (t, OCH2CH2); 2.71 (s, Ac). Anal. calc. for
C22H18N6O4 (430.4): C 61.39, H 4.21, N 19.52; found: C 61.07, H 4.27, N 19.64.
14. N-{Methyl-4-[2-(4-nitrophenyl)ethoxy]pteridin-2-yl}acetamide (29). As described in Exper. 7.1, with N2-
acetyl-7-methylpterin (13; 0.22 g, 1 mmol): 0.252 g (86%) of 29. Colorless crystals. M.p. 213 2158. Rf (CHCl3/
MeOH 9 :1) 0.72. 1H-NMR (CDCl3): 8.65 (d, HÀC(6)); 8.21 (d, 2 Ho to NO2); 8.17 (br. s, NH); 7.54 (d, 2 Hm to
NO2); 4.88 (t, OCH2CH2); 3.40( t, OCH2CH2); 2.81 (s, MeÀC(7)); 2.70( s, Ac). Anal. calc. for C17H16N6O4
(368.4): C 55.43, H 4.38, N 22.81; found: C 55.33, H 4.49, N 22.39.
15. N-{6,7-Dimethyl-4-[2-(4-nitrophenyl)ethoxy]pteridin-2-yl}acetamide (30). As described in Exper. 7.1,
with 15 (0.232 g, 1 mmol): 0.272 g (74%) of 30. Colorless crystals. M.p. 220 222 8 (dec.). Rf (CHCl3/MeOH 9 :1)
0.46. 1H-NMR (CDCl3): 8.21 (d, 2 Ho to NO2); 8.05 (br. s, NH); 7.54 (d, 2 Hm to NO2); 4.87 (t, OCH2CH2); 3.39
(t, OCH2CH2); 2.77 (s, MeÀC(7)); 2.75 (s, MeÀC(6)); 2.68 (s, Ac). Anal. calc. for C18H18N6O4 (382.4): C 56.54,
H 4.74, N 21.98; found: C 56.04, H 4.70, N 21.55.
16. N-{4-[2-(4-Nitrophenyl)ethoxy]-6,7-diphenylpteridin-2-yl}acetamide (31). As described in Exper. 7.1,
with 17 (0.416 g, 1 mmol) at 75 808 for 24 h. CC gave as the first fraction 37 (see Exper. 22) and as the second,
main fraction 0.368 g (69%) of 31. Colorless crystals. M.p. 255 2578. Rf (CHCl3/MeOH 9 :1) 0.75. 1H-NMR
(CDCl3): 8.23 (d, 2 Ho to NO2); 8.12 (br. s, NH); 7.61 7.31 (m, 12 H, Hm to NO2, arom. H); 4.87 (t, OCH2CH2);
3.40( t, OCH2CH2); 2.69 (s, Ac). Anal. calc. for C28H22N6O4 ¥ 1.5 H2O (533.6): C 63.04, H 4.69, N 15.74; found: C
63.28, H 4.37, N 15.44.
17. N2,N2-Dimethyl-4-[2-(4-nitrophenyl)ethoxy]pteridin-2-amine (32). As described in Exper. 7.1, with
N2,N2-dimethylpterin (18; 0.192 g, 1 mmol). Recrystallization from MeOH gave 0.288 g (84%) of 32. Orange
crystals. M.p. 192 1948. Rf (CHCl3/MeOH 9 :1) 0.74. 1H-NMR (CDCl3): 8.73 (d, HÀC(7)); 8.39 (d, HÀC(6));
8.16 (d, 2 Ho to NO2); 7.47 (d, 2 Hm to NO2); 4.80( t, OCH2CH2); 3.36 (t, OCH2CH2); 3.30( s, Me2N). Anal. calc.
for C16H16N6O3 (340.3): C 56.47, H 4.74, N 24.96; found: C 56.34, H 4.69, N 24.50.
18. N2,N2,6,7-Tetramethyl-4-[2-(4-nitrophenyl)ethyoxy]pteridin-2-amine (33). As described in Exper. 7.1,
with N2,N2,6,7-tetramethylpterin (19; 0.22 g, 1 mmol): 0.222 g (60%) of 33. Yellow crystals. M.p. 190 191 8. Rf
(CHCl3/MeOH 9 :1) 0.43. 1H-NMR (CDCl3): 8.15 (d, 2 Ho to NO2); 7.45 (d, 2 Hm to NO2); 4.80( t, OCH2CH2);
3.34 (t, CH2CH2); 3.28 (s, Me2N); 2.64 (s, MeÀC(7)); 2.61 (s, MeÀC(6)). Anal. calc. for C18H20N6O3 (368.4): C
58.69, H 5.47, N 22.81; found: C 58.15, H 5.35, N 22.48.