Réaction #1994273

Équation de réaction

( 3 )

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

cyclohexene

sulfurylchloride

N2

NaN3

→

( 4 )

Rendement 37.0%

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

Rendement 37.0%

Solvants

CH2Cl2

Conditions de réaction

Traitement

1. 1
   Autrethe full consumption of the nucleoside (3)
2. 2
   AutreThe solvent was evaporated
3. 3
   workup.WAITthe residue was subjected to high vacuum for 20 min
4. 4
   workup.DISSOLUTIONIt was then redissolved in dry DMF (3 ml)
5. 5
   AutreThe reaction was quenched with CH2Cl2
6. 6
   Lavagethe organic layers were washed with sat aq. NaCl solution
7. 7
   AutreAfter removing the solvent
8. 8
   workup.DISSOLUTIONthe resulting yellow gum was redissolved in THF (2 ml)
9. 9
   workup.ADDITIONtreated with TBAF (1M in THF, 0.5 ml) at room temperature for 30 min
10. 10
    AutreThe solvent was removed
11. 11
    ExtractionThe aqueous layer was extracted three times with CH2Cl2
12. 12
    AutrePurification by chromatography on silica (EtOAc: petroleum ether 1:1 to EtOAc)

Mode opératoire

To a solution of (3) (348 mg, 0.63 mmol) and cyclohexene (0.32 ml, 3.2 mmol) in dry CH2Cl2 (5 ml) at 4° C., sulfurylchloride (1M in CH2Cl2, 0.76 ml, 0.76 mmol) was added drop wise under N2. After 10 min TLC indicated the full consumption of the nucleoside (3). The solvent was evaporated and the residue was subjected to high vacuum for 20 min. It was then redissolved in dry DMF (3 ml) and treated with NaN3 (205 mg, 3.15 mmol). The resulting suspension was stirred under room temperature for 2 h. The reaction was quenched with CH2Cl2 and the organic layers were washed with sat aq. NaCl solution. After removing the solvent, the resulting yellow gum was redissolved in THF (2 ml) and treated with TBAF (1M in THF, 0.5 ml) at room temperature for 30 min. The solvent was removed and the reaction worked up with CH2Cl2 and sat. aq. NaHCO3 solution. The aqueous layer was extracted three times with CH2Cl2. Purification by chromatography on silica (EtOAc: petroleum ether 1:1 to EtOAc) gave (4) (100 mg, 37%) as a pale yellow foam. 1H NMR (d6 DMSO) δ 2.15-2.26 (m, 2H, H-2′), 3.47-3.57 (m, 2H, H-5′), 3.88-3.90 (m, 1H, H-4′), 4.14 (d, J=4.7 Hz, 2H, CH2NH), 4.24-4.27 (m, 1H, H-3′), 4.75 (s, 2H, CH2N3), 5.14 (t, J=5.2 Hz, 1H, OH), 5.96-6.00 (m, 1H, H-1′), 8.10 (s, 1H, H-6), 10.00 (s, 1H, NHCOCF3)), 11.26 (s, 1H, NH).

Source