Lithium borohydride → HCID 22224443, compound

HRID 638875Notes

Reaction equation

HRID 638875 reaction equation
[Li+].[BH4-].[CH3:3][N:4]1[C:8]2[CH:9]=[CH:10][CH:11]=[CH:12][C:7]=2[N:6]2[CH:13]=[C:14]([C:16](OCC)=[O:17])[N:15]=[C:5]12>C1COCC1.C(Cl)Cl.O=[Mn]=O>[CH3:3][N:4]1[C:8]2[CH:9]=[CH:10][CH:11]=[CH:12][C:7]=2[N:6]2[CH:13]=[C:14]([CH:16]=[O:17])[N:15]=[C:5]12

Participants

6

Reactant 2

HCID 4148881Lithium borohydrideHCID 22224503HCID 22224503, compound

Product 1

HCID 22224443HCID 22224443, compound

Reagents, catalysts & solvents 3

HCID 14801Manganese dioxideCatalystHCID 6344DichloromethaneSolventHCID 8028TetrahydrofuranSolvent

Procedure

To stirred solution of LiBH4 (1.79 g, 82 mmol) in THF at 0° C., ethyl 9-methyl-9H-imidazo[1,2-a]benzimidazole-2-carboxylate (2.5 g, 10.3 mmol) was added drop wise. The reaction mixture was refluxed for 2 hrs and cooled to room temperature. Ti was carefully quenched with ice cold water and acidified with Con. HCl to pH 4. The reaction mixture was stirred at room temperature for 1 hr and basified with K2CO3. The residue was extracted with chloroform:methanol (3:1) and dried over anhydrous MgSO4. It was filtered and concentrated. Yield. 1.3 g (65%). (M+H) 202. The residue (1.3 g, 6.4 mmol) was oxidised with MnO2 (5.0 g) in CH2Cl2 under refluxing condition. After the completion, reaction mixture was filtered and concentrated. It was purified by SiO2 column chromatography by eluting it with 1:1 ethyl acetate:hexane. Brown solid. Yield. 330 mg (25%); (M+H) 200.

Workup

  1. temperatureThe reaction mixture was refluxed for 2 hrs
  2. customTi was carefully quenched with ice cold water
  3. extractionThe residue was extracted with chloroform:methanol (3:1)
  4. dry with materialdried over anhydrous MgSO4
  5. filtrationIt was filtered
  6. concentrationconcentrated
  7. customYield
  8. temperatureunder refluxing condition
  9. customAfter the completion, reaction mixture
  10. filtrationwas filtered
  11. concentrationconcentrated
  12. customIt was purified by SiO2 column chromatography
  13. washby eluting it with 1:1 ethyl acetate
  14. customYield

Sources & evidence

ORD record
ord-5690349dafc9495aac8263c1d806bb4c
Source dataset
uspto-grants-2010_04
Patent number
US07691842B2

Reaction notes

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