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H. Li et al.
recrystallization twice from 95% ethanol gave gray needle-like crystals (5)
1
1.53 g in 75% yield. Mp 274–2768C. H NMR (500 MHz, DMSO-d6) d
(ppm): 13.1 (s, 1H, COOH), 8.54 (m, 4H), 7.91 (t, J ¼ 7.8 Hz, 2H), 4.74
(s, 2H); ESI-MS (m/z, %): 254.2 (M þ H)þ. IR (KBr) n: 3446, 3285, 1607,
1317, 762, 671 cm21
;
UV-vis (H2O, lmax
,
1): 234 nm, 2.9 ꢀ
104 l mol21 cm21; 343 nm, 1.4 ꢀ 104 l mol21 cm21
.
1,8-Naphthalimide-N-butyric Acid (7b)
Compound (7b) was synthesized similar to the procedure for 7a. White solid
1
was obtained; the yield was 83%. Mp 186–1888C. H NMR (300 MHz,
DMSO-d6) d (ppm): 11.98 (s, 1H, COOH), 8.55 (m, 4H), 7.88 (t, J ¼ 7.7 Hz,
2H), 4.15 (t, Jbg ¼ 6.86 Hz, 2H, gH), 2.31 (t, 2H, aH), 1.91 (m, 2H, bH);
ESI-MS (m/z, %): 284.2 [(M þ H)þ, 80], 306.2 [(M þ Na)þ, 50)].
1,8-Naphthalimide-N-caproic Acid (7c)
Compound (7c) was synthesized similarly according to the procedure for 7a.
1
White solid was obtained; the yield was 63%. Mp 134–1368C. H NMR
(500 MHz, DMSO-d6) d (ppm): 12.0 (s, 1H, COOH), 8.49 (m, 4H), 7.88
(t, J ¼ 7.7 Hz, 2H), 4.04 (t, Jv,d ¼ 7.4 Hz, 2H, vH), 2.22(t, Jab ¼ 7.3 HZ,
2H, aH), 1.64 (m, 2H, dH), 1.55 (m, 2H, bH), 1.35 (m, 2H, gH); ESI-MS
(m/z, %): 312.2 [(M þ H)þ, 100], 334.2 [(M þ Na)þ, 45)] IR (KBr) n:
3456, 3478, 1702, 1649, 1238, 780 cm21; UV-vis (H2O, l max, 1): 234
nm, 3.8 ꢀ 104 1 mol21 cm21; 343 nm, 1: 1.3 ꢀ 104 1 mol21 cm21
.
20-[2-(1,8-Naphthalimide)acetamide]-20-deoxyuridine (8a)
To a solution of (7a) (76.5 mg; 0.3 mmol), 20-amino-20-deoxyuridine (5) (72.9
mg, 0.3 mmol), six drops of triethylamine and HOBt (81.07 mg, 0.6 mmol)
in CH2Cl2 (8 ml)/THF (5ml) were added EDC (115mg, 0.6 mmol). The
reaction mixture was stirred at room temperature overnight and monitored by
TLC (CH2Cl2/CH3OH ¼ 5/1, v/v), and the precipitates formed. The
solvents evaporated in vacuo, and then the residue was chromatographed on a
silica-gel column with eluent (CH2Cl2/CH3OH ¼ 40/1, v/v) to give a white
1
solid (92 mg in 64% yield). Mp 278–2808C (dec.). H NMR (300 MHz,
DMSO-d6) d (ppm): 8.45 (m, 4H), 8.29 (d, J5,6 ¼ 8.01 Hz, 1H, H6), 7.84
(m, 2H), 5.93 (d, J1 ,2 ¼ 8.01 Hz, 1H, H10), 5.58 (d, J6,5 ¼ 8.01 Hz, 1H, H5),
4.68 (m, 2H, Ha), 4.51 (m, 1H, H20), 4.08 (m, 1H, H30), 3.90 (m, 1H, H40),
3.55 (m, 2H, H50). ESI-MS (m/z, %): 481.2 [(M þ H)þ, 50)], 503.2
[(M þ Na)þ, 100)].
0
0