Reaction #1951033

Reaction equation

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

sodium methoxide

→

4.48

Yield 56.3%

2,5,6-Trichloro-3-trifluoroacetyl-1-(β-D-ribofuranosyl)indole

Yield 56.3%

Solvents

MeOH CHCl3

MeOH

MeOH CHCl3

Conditions

Workup

1. 1
   Otherthe solvent was removed under vacuum
2. 2
   Extractionwater (5 mL), and the suspension extracted with EtOAc (2×50 mL)
3. 3
   DryingThe combined organic extracts were dried over MgSO4
4. 4
   Filtrationfiltered
5. 5
   Otherevaporated
6. 6
   Otherto yield a yellow-orange solid
7. 7
   workup.ADDITIONFractions containing product
8. 8
   Otherevaporated
9. 9
   Otherto yield a white solid which
10. 10
    Otherwas recrystallized from MeOH/H2O

Procedure

2,5,6-Trichloro-3-trifluoroacetyl-1-(5-O-acetyl-β-D-ribofuranosyl)indole (4.45, 94 mg, 0.19 mmol) was dissolved in dry MeOH (20 mL) to which was added sodium methoxide (12 mg, 0.22 mmol). The solution was stirred at room temperature for 90 min, then the solvent was removed under vacuum. The residue was suspended in brine (40 mL) and water (5 mL), and the suspension extracted with EtOAc (2×50 mL). The combined organic extracts were dried over MgSO4, filtered and evaporated to yield a yellow-orange solid. The solid was dissolved in 10% MeOH/CHCl3 (1 mL) and subjected to column chromatography (40×350 mm) on silica gel with 10% MeOH/CHCl3. Fractions containing product were pooled and evaporated to yield a white solid which was recrystallized from MeOH/H2O to yield 48 mg (56%) of 4.48 as a pale yellow powder: mp 179-180 C; Rf0.3 (10% MeOH/CHCl3); 1H-NMR (500 MHz, DMSO-d6): δ 8.80 (s, 1H), 8.23 (s, 1H), 6.14 (d, 1H), 5.50 (b, 2H, D2O exch.), 5.34 (b, 1H, D2O exch.), 4.44 (t, 1H), 4.19 (dd, 1H), 4.06 (d, 1H), 3.76 (dq, 2H). 13C-NMR (125 MHz, DMSO-d6): δ 173.47 (J=37 Hz), 132.34, 132.65, 127.38, 127.28, 125.47, 121.35, 116.29, 115.88 (J=289 Hz), 106.90, 89.42, 86.88, 71.96, 69.49, 60.86. 19F-NMR (300 MHz, DMSO-d6): δ −72.34. HRMS (EI) m/z calcd. for C15H11Cl3F3NO5 446.9655, found 446.9661. Anal calcd for C15H11Cl3F3NO5: C, 40.16; H, 2.47; N, 3.12. Found: C, 40.18; H, 2.60; N, 2.98.

Source