Reaktion #1994272

Reaktionsgleichung

( 2 )

5′-O-(tert-butyidimethylsilyl)-5-[3-(2,2,2-trifluoroacetamido)-prop-1-ynyl]-2′-deoxyuridine

acetic acid

acetic anhydride

DMSO

→

oil

Ausbeute 89.0%

5′-O-(tert-Butydimethylsilyl)-3′-O-methylthiomethyl-5-[3-(2,2,2-trifluoroacetamido)-prop-1-ynyl]-2′-deoxyuridine

Ausbeute 89.0%

Reaktionsbedingungen

Aufarbeitung

1. 1
   Sonstigewas quenched with sat. aq. NaHCO3
2. 2
   workup.ADDITIONEtOAc (50 ml) was added
3. 3
   Extraktionthe aqueous layer was extracted three times with ethyl acetate
4. 4
   WaschenThe combined organic layers were washed with sat. aq. NaHCO3 solution
5. 5
   Trocknendried (MgSO4)
6. 6
   SonstigeAfter removing the solvent under reduced pressure
7. 7
   Sonstigethe product (3) was purified by chromatography on silica (EtOAc: petroleum ether 8:2)

Vorschrift

To a solution of (2) (1.84 g, 3.7 mmol) in dry DMSO (7 ml) was added acetic acid (3.2 ml) and acetic anhydride (10.2 ml). The mixture was stirred for 2 days at room temperature, before it was quenched with sat. aq. NaHCO3. EtOAc (50 ml) was added and the aqueous layer was extracted three times with ethyl acetate. The combined organic layers were washed with sat. aq. NaHCO3 solution and dried (MgSO4). After removing the solvent under reduced pressure, the product (3) was purified by chromatography on silica (EtOAc: petroleum ether 8:2) yielding a clear sticky oil (1.83 g, 89%). 1H NMR (d6 DMSO): δ 0.00 (s, 6H, CH3), 0.79 (s, 9H, tBu), 1.96-2.06 (m, 1H, H-2′), 1.99 (s, 3H, SCH3), 2.20-2.26 (m, 1H, H-2′), 3.63-3.74 (m, 2H, H-5′), 3.92-3.95 (m, 1H, H-4′), 4.11-4.13 (m, 2H, CH2), 4.28-4.30 (m, 1H, H-3′), 4.59 (br s, 2H, CH2), 5.97 (t, J=6.9 Hz, 1H, H-1′), 7.85 (s, 1H, H-6), 9.95 (t, J=5.3 Hz, 1H, NH), 11.64 (s, 1H, NH). Mass (−ve electrospray) calcd for C22H32F3N3O6SSi 551.17. Found 550.

Quelle