Dimethyl Sulfoxide → N4-Benzoyl-3'-O-(methylthiomethyl)-5'-O-(tert-butyldimethylsilyl)-2'-deoxycytidine

HRID 634079Notes

Reaction equation

HRID 634079 reaction equation
[C:1]([NH:9][C:10]1[CH:30]=[CH:29][N:13]([C@@H:14]2[O:28][C@H:18]([CH2:19][O:20][Si:21]([C:24]([CH3:27])([CH3:26])[CH3:25])([CH3:23])[CH3:22])[C@@H:16]([OH:17])[CH2:15]2)[C:12](=[O:31])[N:11]=1)(=[O:8])[C:2]1[CH:7]=[CH:6][CH:5]=[CH:4][CH:3]=1.[CH3:32][S:33]([CH3:35])=O.C(OC(=O)C)(=O)C.C([O-])(O)=O.[Na+]>CCOC(C)=O.C(O)(=O)C>[C:1]([NH:9][C:10]1[CH:30]=[CH:29][N:13]([C@@H:14]2[O:28][C@H:18]([CH2:19][O:20][Si:21]([C:24]([CH3:25])([CH3:26])[CH3:27])([CH3:23])[CH3:22])[C@@H:16]([O:17][CH2:32][S:33][CH3:35])[CH2:15]2)[C:12](=[O:31])[N:11]=1)(=[O:8])[C:2]1[CH:3]=[CH:4][CH:5]=[CH:6][CH:7]=1

Participants

7

Procedure

3.5 g N4-benzoyl-5′-O-tert-butyldimethylsilyl-2′-deoxycytidine (5c) (7.65 mmol) was dissolved in a mixture consisting of 14.7 mL DMSO, 6.7 mL acetic acid, and 21.59 mL acetic anhydride and stirred for 48 h at room temperature. During this period of time, a complete conversion to product was observed by TLC (Rf=0.4, EtOAc:hex/10:1). The mixture was then neutralized with a saturated NaHCO3 solution and extracted with CH2Cl2 (3×100 mL). The combined organic extract was then washed with saturated solution of NaHCO3 and dried over Na2SO4, and concentrated under vacuum. The product was then purified by silica gel column chromatography (EtOAc:hex/2:1 to 9:1) to obtain N4-benzoyl-3′-O-(methylthiomethyl)-5′-O-(tert-butyldimethylsilyl)-2′-deoxycytidine (6c) as white powder in 73% yield (2.9 g, Rf=0.6, EtOAc:hex/9:1). HR-MS: obs. m/z 506.2134, cald. for C24H36O5N3SiS [M+H]+. 506.2145. 1H-NMR (CDCl3): δH 8.43 (d, J=7.1 Hz, 1H), 7.93 (m, 2H), 7.64 (m, 1H), 7.54 (m, 3H), 6.30 (m, 1H), 4.62 & 4.70 (2×d, J=11.59 Hz, 2H), 4.50 (m, 1H), 4.19 (m, 1H), 3.84 & 3.99 (2×dd, J=11.59 & 2.79 Hz, 2H), 2.72 (m, 1H), 2.21 (m, 1H), 2.14 (s, 3H), 0.99 (s, 9H), and 0.16 (s, δH) ppm.

Workup

  1. waitDuring this period of time
  2. extractionextracted with CH2Cl2 (3×100 mL)
  3. extractionThe combined organic extract
  4. washwas then washed with saturated solution of NaHCO3
  5. dry with materialdried over Na2SO4
  6. concentrationconcentrated under vacuum
  7. customThe product was then purified by silica gel column chromatography (EtOAc:hex/2:1 to 9:1)

Sources & evidence

ORD record
ord-8d82fb1365314aa189dacf6bcbb795b4
Source dataset
uspto-grants-2016_04
Patent number
US09322050B2

Reaction notes

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