Reaktion #987244

Reaktionsgleichung

59

5-chloro-7-(4-nitrobenzylsulfanyl)-3-(2′, 3′, 5′-tri-O-acetyl-β-D-ribofuranosyl)-3H-imidazo[4,5-b]pyridine

ammonia

→

61

Ausbeute 88.0%

5-Chloro-7-(4-nitro-benzylsulfanyl)-3-β-D-ribofuranosyl-3H-imidazo[4,5-b]pyridine

Ausbeute 88.0%

Lösungsmittel

methanol

Reaktionsbedingungen

Vorschrift

A mixture of 57 (75 mg, 0.17 mmol), p-nitro-benzylthiol (0.85 g, 0.5 mmol) and 0.1 mL of Et3N in 5 mL of DMF was stirred at room temperature for 18 h. under N2 atmosphere. The solution was extracted with ether, dried and purified by flash chromatography (PE/EA. 1:1), yielding 72 mg of 5-chloro-7-(4-nitrobenzylsulfanyl)-3-(2′, 3′, 5′-tri-O-acetyl-β-D-ribofuranosyl)-3H-imidazo[4,5-b]pyridine 59 (75%). 1H NMR (CDCl3): δ 8.19 (d, 2H, J=8.0), 8.15(s, 1H), 7.60 (s, 1H), 755 (d, 2H, J=8.0, 2H), 6.21 (d, 1H, J=5.1 Hz), 5.83 (dd, 1H, J=5.1, 5.9 Hz), 5.64 (dd, 1H, J=5.1, 5.9 Hz), 4.63 (s, 2H), 4.38 (m, 2H), 2.14, 2.12, 2.08 (3×s, 3H). Deprotection of 59 with saturated solution of ammonia in methanol at 0° C. for 18 h, gave 50 mg 61 (88%). 1H NMR (CDCl3): δ 8.74 (s, 1H), 8.14 (d, 2H, J=8.0), 7.66 (d, 2H, J=8.0, 2H), 7.18 (s, 1H), 6.03 (d, 1H, J=5.1 Hz), 4.89 (s, 2H), 4.69 (dd, 1H, J=5.1, 5.9 Hz), 4.43 (m 1H), 3.88-3.78 (m, 2H). 13C NMR (CD3OD): 147.15, 145.80, 145.101, 144.324, 137.180, 130.02, 129.78, 128.75, 115.495, 90.91, 87.49, 75.46, 72.16, 63.13, 36.07; Mp: 162-165° C.; HRMS calc. for C18H18N4O6ClS m/z=453.0635 (M+H), found 453.0614.

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