Reacción #1951020

Ecuación de reacción

MeOH CHCl3

MeOH H2O

sodium methoxide

2,5,6-Trichloro-3-formyl-1-(5-O-acetyl-β-D-ribofuranosyl)indole

→

4.25

Rendimiento 42.0%

5,6-Dichloro-2-methoxy-3-formyl-1-(β-D-ribofuranosyl)indole

Rendimiento 42.0%

Disolventes

MeOH

MeOH

MeOH

Condiciones de reacción

Tratamiento posterior

1. 1
   Otrothe solvent was removed under vacuum
2. 2
   Extracciónthe suspension extracted with EtOAc (2×50 mL)
3. 3
   SecadoThe combined organic extracts were dried over MgSO4
4. 4
   Filtraciónfiltered
5. 5
   Otroevaporated
6. 6
   Otroto yield a white solid
7. 7
   workup.ADDITIONFractions containing product
8. 8
   Otroevaporated
9. 9
   Otroto yield a white solid (the balance of recovered material
10. 10
    workup.ADDITIONFractions containing product
11. 11
    Otroevaporated

Procedimiento

2,5,6-Trichloro-3-formyl-1-(5-O-acetyl-β-D-ribofuranosyl)indole (see Chen et al.; 4.24, 148 mg, 0.35 mmol) was dissolved in dry MeOH (20 mL) to which was added sodium methoxide (21 mg, 0.39 mmol). The solution was stirred at room temperature for 30 min, then the solvent was removed under vacuum. The residue was suspended in 10% aqueous NaHCO3, and the suspension extracted with EtOAc (2×50 mL). The combined organic extracts were dried over MgSO4, filtered and evaporated to yield a white solid. The solid was dissolved in MeOH (1 mL) and subjected to column chromatography (40×350 mm) on silica gel with 20% MeOH/CHCl3. Fractions containing product were pooled and evaporated to yield a white solid (the balance of recovered material was the deprotected 2-chloro derivative). The crude product was dissolved in MeOH and subjected to column chromatography (40×350 mm) on C18-reverse phase silica gel with 75% MeOH/H2O. Fractions containing product were pooled and evaporated to yield 50 mg (42%) of 4.25 as a white crystalline solid: mp 198-199° C.; Rf0.2 (10% MeOH/CHCl3); 1H-NMR (500 MHz, DMSO-d6): δ 10.21 (s, 1H), 8.34 (s, 1H), 8.31 (s, 1H), 5.84 (d, 1H), 5.41 (d, 1H, D2O exch.), 5.30 (t, 1H, D2O exch.), 5.23 (d, 1H, D2O exch.), 4.41 (s, 4H), 4.13 (s, 1H), 3.95 (d, 1H), 3.69 (m, 2H). 13C-NMR (125 MHz, DMSO-d6): δ 183.28, 160.04, 129.51, 125.21, 124.83, 124.68, 121.12, 114.73, 100.30, 86.81, 85.93, 71.06, 69.75, 64.78, 61.18. HRMS (EI) m/z calcd. for C15H15Cl2NO6 375.0276, found 375.0278. Anal calcd for C15H15Cl2NO6: C, 47.89; H, 4.02; N, 3.72. Found: C, 47.73; H, 4.12; N, 3.72.

Fuente