Trimethylsilyl triflate → HCID 53745225, compound

HRID 1281699Notes

Reaction equation

HRID 1281699 reaction equation
[Br:1][C:2]1[NH:3][C:4]2[CH:10]=[C:9]([Cl:11])[C:8]([Cl:12])=[CH:7][C:5]=2[N:6]=1.C/C(/O[Si](C)(C)C)=N\[Si](C)(C)C.FC(F)(F)S(O[Si](C)(C)C)(=O)=O.C(O[CH:41]1[O:54][CH2:53][C@@H:48]([O:49][C:50](=[O:52])[CH3:51])[C@@H:43]([O:44][C:45](=[O:47])[CH3:46])[CH2:42]1)(=O)C.C(=O)(O)[O-].[Na+]>ClCCCl>[Br:1][C:2]1[N:3]([C@H:41]2[O:54][CH2:53][C@@H:48]([O:49][C:50](=[O:52])[CH3:51])[C@@H:43]([O:44][C:45](=[O:47])[CH3:46])[CH2:42]2)[C:4]2[CH:10]=[C:9]([Cl:11])[C:8]([Cl:12])=[CH:7][C:5]=2[N:6]=1

Participants

7

Reactant 5

HCID 65367Trimethylsilyl triflateHCID 4660172-bromo-5,6-dichloro-1H-benzimidazoleHCID 516892Sodium BicarbonateHCID 6913588N,O-bis(trimethylsilyl)acetamideHCID 11086487D-erythro-Pentopyranose, 2-deoxy-, 1,3,4-triacetate

Product 1

HCID 53745225HCID 53745225, compoundYield 52%

Reagents, catalysts & solvents 1

HCID 111,2-DichloroethaneSolvent

Conditions

Temperature
50 °C

Procedure

As described in General Procedure III, 2-bromo-5,6-dichlorobenzimidazole (0.52 g, 2.0 mmol), N,O-bis(trimethylsilyl) acetamide (Aldrich, 0.53 ml, 2.2 mmol), and 1,2-dichloroethane (Aldrich Sure Seal, 20 ml) were combined and refluxed under nitrogen for 0.25 h. The solution was cooled to 50° C. and trimethylsilyl trifluoromethanesulfonate (Aldrich, 0.42 ml, 2.2 mmol) was added. Immediately, 0.51 g (2.0 mmol) solid 1,3,4-tri-O-acetyl-2-deoxy-D-erythro-pentopyranose (as prepared and described by R. Allerton and W. G. Overend in J. Chem. Soc. 1951, 1480-1484) was added. The solution was stirred under nitrogen at 50° C. for 0.5 h, then poured into 7% aqueous sodium bicarbonate and extracted with dichloromethane. The organic layer was dried with magnesium sulfate (anhyd), filtered, and evaporated. The crude residue was purified on a silica gel column eluting with a step gradient of 0.1% to 1% methanol in dichloromethane to give 0.47 g (1.0 mmol, 52% yield) 2-bromo-5,6-dichloro-1-(3,4-di-O-acetyl-2-deoxy-alpha-D-erythro-pentopyranosyl)-1H-benzimidazole; 1H NMR (CD3OD) δ8.11 (s, 1H), 7.80 (s, 1H), 6.11-6.07 (dd, 1H), 5.37-5.32 (m, 2H), 4.24-4.19 (dd, 1H), 4.05-4.00 (dd, 1H), 2.68-2.56 (q, 1H), 2.32 (s, 3H), 2.20-2.15 (m, 1H), 2.01 (s, 3H); and 0.13 g (0.28 mmol, 14% yield) 2-bromo-5,6-dichloro-1-(3,4-di-O-acetyl-2-deoxy-beta-D-erythro-pentopyranosyly)-1H-benzimidazole; 1H NMR (CD3OD) δ8.02 (s, 1H), 7.76 (s, 1H), 6.13-6.10 (d, 1H), 5.62 (bs, 1H), 5.29-5.23 (m, 1H), 4.15-4.03 (m, 2H), 2.76-2.70 (t, 1H), 2.19 (s, 3H), 2.15-2.1 (m, 1H), 2.00 (s, 3H).

Workup

  1. temperaturerefluxed under nitrogen for 0.25 h
  2. extractionextracted with dichloromethane
  3. dry with materialThe organic layer was dried with magnesium sulfate (anhyd)
  4. filtrationfiltered
  5. customevaporated
  6. customThe crude residue was purified on a silica gel column
  7. washeluting with a step gradient of 0.1% to 1% methanol in dichloromethane

Sources & evidence

ORD record
ord-518ce3fca8c9418782c7efd002b51aac
Source dataset
uspto-grants-2002_09
Patent number
US06455507B1

Reaction notes

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