Dimethylformamide → 5,6-Dichloro-2-ethenyl-1-(2,3-di-O-acetyl-5-deoxy-beta-D-ribofuranosyl) 1H-benzimidazole

HRID 2227202Notes

Reaction equation

HRID 2227202 reaction equation
Br[C:2]1[N:6]([C@@H:7]2[O:19][C@H:18]([CH3:20])[C@@H:13]([O:14][C:15](=[O:17])[CH3:16])[C@H:8]2[O:9][C:10](=[O:12])[CH3:11])[C:5]2[CH:21]=[C:22]([Cl:26])[C:23]([Cl:25])=[CH:24][C:4]=2[N:3]=1.[CH:27]([Sn](CCCC)(CCCC)CCCC)=[CH2:28].CN(C=O)C>C1C=CC([P]([Pd]([P](C2C=CC=CC=2)(C2C=CC=CC=2)C2C=CC=CC=2)([P](C2C=CC=CC=2)(C2C=CC=CC=2)C2C=CC=CC=2)[P](C2C=CC=CC=2)(C2C=CC=CC=2)C2C=CC=CC=2)(C2C=CC=CC=2)C2C=CC=CC=2)=CC=1.ClCCl>[Cl:25][C:23]1[C:22]([Cl:26])=[CH:21][C:5]2[N:6]([C@@H:7]3[O:19][C@H:18]([CH3:20])[C@@H:13]([O:14][C:15](=[O:17])[CH3:16])[C@H:8]3[O:9][C:10](=[O:12])[CH3:11])[C:2]([CH:27]=[CH2:28])=[N:3][C:4]=2[CH:24]=1

Participants

6

Reactant 3

HCID 6228DimethylformamideHCID 81998TributylvinyltinHCID 699962602-Bromo-5,6-dichloro-1-(5-deoxy-2,3-di-O-acetyl-beta-D-ribofuranosyl)benzimidazole

Product 1

HCID 701789275,6-Dichloro-2-ethenyl-1-(2,3-di-O-acetyl-5-deoxy-beta-D-ribofuranosyl) 1H-benzimidazoleYield 51.1%

Reagents, catalysts & solvents 2

HCID 178418397HCID 178418397, compoundCatalystHCID 6344DichloromethaneSolvent

Conditions

Temperature
90 °C

Procedure

2-Bromo-5,6-dichloro-1-(2,3-di-O-acetyl-5-deoxy-beta-D-ribofuranosyl)-1H-benzimidazole (0.22 g, 0.47 mmol), vinyltributyltin (Aldrich, 0.5 ml, 2.4 mmol), tetrakis(triphenylphosphine)palladium(0) (Aldrich, 0.054 g, 0.047 mmol) and DMF (Aldrich Sure Seal, 5 mL) were combined and flushed with argon for 30 min. The solution was warmed to 90° C. After 1 h the DMF was distilled off under reduced pressure. The residue was taken up in ethyl acetate (50 mL) and extracted with 20 mL of saturated NH4Cl. The organic layer was dried with magnesium sulfate (anhyd), filtered, and evaporated. The crude residue was purified on a silica gel column (2.5×14 cm, 230-400 mesh) with 1:40 methanol:dichloromethane to give the title compound (0.1 g, 0.24 mmol, 51%); MS (ES+): m/z (rel. intensity) 436 (100, M++Na); 1H NMR (DMSO-d6) δ8.06 (s,1H, ArH), 7.97 (s, 1H, ArH), 7.10 (dd, 1H, CH, J=11 Hz, J=16.8 Hz), 6.50 (dd, 1H, CH, J=1.8 Hz, J=16.8 Hz), 6.32 (d, 1H, CH, J=6.9 Hz), 5.85 (dd, 1H, CH, J=1.8 Hz, J=11 Hz), 5.51 (apparent triplet, 1H, CH, J=7.0 Hz), 5.27 (apparent triplet, 1H, CH, J=6.5 Hz), 4.27-4.18 (m, CH, 1H), 2.15 (s, 3H, OAc), 1.99 (s, 3H, OAc), 1.53 (d, 3H, CH3, J=6.3 Hz).

Workup

  1. customflushed with argon for 30 min
  2. distillationAfter 1 h the DMF was distilled off under reduced pressure
  3. extractionextracted with 20 mL of saturated NH4Cl
  4. dry with materialThe organic layer was dried with magnesium sulfate (anhyd)
  5. filtrationfiltered
  6. customevaporated
  7. customThe crude residue was purified on a silica gel column (2.5×14 cm, 230-400 mesh) with 1:40 methanol

Sources & evidence

ORD record
ord-35d226dd4c604fba99723e71c5d1f8d2
Source dataset
uspto-grants-2002_07
Patent number
US06413938B1

Reaction notes

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