Trimethylsilyl triflate → 2-Chloro-5,6-dinitro-1-(2,3,5-tri-O-benzyl-beta-D-ribofuranosyl)benzimidazole

HRID 6346

Reaction equation

HRID 6346 reaction equation
[Cl:1][C:2]1[NH:3][C:4]2[CH:10]=[C:9]([N+:11]([O-:13])=[O:12])[C:8]([N+:14]([O-:16])=[O:15])=[CH:7][C:5]=2[N:6]=1.[CH2:17]([O:24][C@@H:25]1[C@H:29]([O:30][CH2:31][C:32]2[CH:37]=[CH:36][CH:35]=[CH:34][CH:33]=2)[C@@H:28]([CH2:38][O:39][CH2:40][C:41]2[CH:46]=[CH:45][CH:44]=[CH:43][CH:42]=2)[O:27][CH:26]1Cl)[C:18]1[CH:23]=[CH:22][CH:21]=[CH:20][CH:19]=1.[Si](OS(C(F)(F)F)(=O)=O)(C)(C)C>CC#N.CCOC(C)=O>[Cl:1][C:2]1[N:3]([C@@H:26]2[O:27][C@H:28]([CH2:38][O:39][CH2:40][C:41]3[CH:46]=[CH:45][CH:44]=[CH:43][CH:42]=3)[C@@H:29]([O:30][CH2:31][C:32]3[CH:37]=[CH:36][CH:35]=[CH:34][CH:33]=3)[C@H:25]2[O:24][CH2:17][C:18]2[CH:23]=[CH:22][CH:21]=[CH:20][CH:19]=2)[C:4]2[CH:10]=[C:9]([N+:11]([O-:13])=[O:12])[C:8]([N+:14]([O-:16])=[O:15])=[CH:7][C:5]=2[N:6]=1

Participants

6

Reactant 3

HCID 65367Trimethylsilyl triflateHCID 2678102-Chloro-5,6-dinitrobenzimidazoleHCID 544989072,3,5-tri-O-benzyl-D-ribofuranosyl chloride

Product 1

HCID 540450672-Chloro-5,6-dinitro-1-(2,3,5-tri-O-benzyl-beta-D-ribofuranosyl)benzimidazoleYield 35%

Reagents, catalysts & solvents 2

HCID 6342AcetonitrileSolvent2×HCID 8857Ethyl AcetateSolvent

Conditions

Temperature
75 °C

Procedure

To a mixture of 0.541 g (2.23 mmol) of 2-chloro-5,6-dinitrobenzimidazole in 12 mL of MeCN, was added 0.558 mL (2.23 mmol) of BSA. The reaction mixture was stirred at 75° C. for 15 min to give a clear solution. This solution was treated with the above MeCN solution of 2,3,5-tri-O-benzyl-D-ribofuranosyl chloride and 0.56 mL (2.90 mmol) of TMSOTf at 75° C. for 30 min. The reaction mixture was cooled and diluted with EtOAc (50 mL). The EtOAc solution was washed with sat. NaHCO3 solution (50 mL×2), sat. NaCl solution (50 mL), dried (Na2SO4), and evaporated. The residue was chromatographed on a silica column (2.2×18 cm, eluted with 20% EtOAc/hexane). Evaporation of fractions 10-14 (20 mL per fraction) gave 0.502 g (35%) of 60 as a syrup. MS: (FAB) m/e 645 (1%, MH+ =645). 1H NMR (DMSO-d6): δ8.50, 8.49 (2×s, 2, 7-H and 4-H), 7.34, 6.90 (2×m, 15, 3×Ph), 6.09 (d, 1, 1'-H, J1'-2' =8.0 Hz), 4.73~4.27 (m, 9, 2'-H, 3'-H, 4'-H, and 3×PhCH2), 3.77 (dd, 1, 5'-H, J4'-5' =2.0 Hz, J5'-5" =11.0 Hz), 3.65 (dd, 1, 5"-H, J4'- 5" =2.5 Hz).

Workup

  1. additionwas added 0.558 mL (2.23 mmol) of BSA
  2. customto give a clear solution
  3. temperatureThe reaction mixture was cooled
  4. washThe EtOAc solution was washed with sat. NaHCO3 solution (50 mL×2), sat. NaCl solution (50 mL)
  5. dry with materialdried (Na2SO4)
  6. customevaporated
  7. customThe residue was chromatographed on a silica column (2.2×18 cm, eluted with 20% EtOAc/hexane)
  8. customEvaporation of fractions 10-14 (20 mL per fraction)

Sources & evidence

ORD record
ord-2985c0e734b84302990b58baa671a5d0
Source dataset
uspto-grants-1993_09
Patent number
US05248672

Linked notes

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