Methanol → HCID 21459061, compound

HRID 2254802Notes

Reaction equation

HRID 2254802 reaction equation
[C:1]([C:3]1[C:4]([O:23]C)=[C:5]([O:21]C)[CH:6]=[C:7]([CH:20]=1)[C:8]([C:10]1[CH:15]=[CH:14][C:13]([C:16]([F:19])([F:18])[F:17])=[CH:12][CH:11]=1)=[O:9])#[N:2].B(Br)(Br)Br.CO>C(Cl)Cl>[C:1]([C:3]1[C:4]([OH:23])=[C:5]([OH:21])[CH:6]=[C:7]([CH:20]=1)[C:8]([C:10]1[CH:11]=[CH:12][C:13]([C:16]([F:17])([F:18])[F:19])=[CH:14][CH:15]=1)=[O:9])#[N:2]

Participants

5

Reactant 3

HCID 887MethanolHCID 25134Boron tribromideHCID 21459178HCID 21459178, compound

Product 1

HCID 21459061HCID 21459061, compound

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent

Procedure

1.5 g 5-cyano-3,4-dimethoxy-4'-(trifluoromethyl)benzophenone (dissolved in 75 ml of methylene chloride) are treated at 5° with 2.18 ml of boron tribromide, whereupon the mixture is stirred at room temperature for 18 hours. The reaction mixture is subsequently diluted with 50 ml of methylene chloride. The mixture is heated under reflux for an additional 4 hours, treated at -70° with 15 ml of methanol, stirred at room temperature for 2 hours, evaporated, the residue is dried in vacuo and partitioned between ethyl acetate and ice-water. The aqueous phase is extracted twice more with ethyl acetate. The combined ethyl acetate phases are dried over sodium sulfate and evaporated. The thus-obtained material is stirred at 130° for 6 hours with 10 ml of acetic anhydride and 1 ml of pyridine. The mixture is evaporated and the residue is partitioned between ice-water and methylene chloride. The methylene chloride phase is dried over sodium sulfate and evaporated, and the residue is chromatographed on 30 g of silica gel with methylene chloride. The thus-obtained diacetate is dissolved in 10 ml of methanol. The solution is treated with 4.2 ml of 1N sodium hydroxide solution, stirred at 0° for 1 hour, neutralized with acetic acid, evaporated and partitioned between ethyl acetate and saturated sodium chloride solution. The ethyl acetate phases are dried over sodium sulfate and evaporated, and the residue is recrystallized from methylene chloride. There is obtained 5-cyano-3,4-dihydroxy-4'-(trifluoromethyl)benzophenone of melting point 204°-206°.

Workup

  1. temperatureThe mixture is heated
  2. temperatureunder reflux for an additional 4 hours
  3. stirringstirred at room temperature for 2 hours
  4. customevaporated
  5. customthe residue is dried in vacuo
  6. custompartitioned between ethyl acetate and ice-water
  7. extractionThe aqueous phase is extracted twice more with ethyl acetate
  8. dry with materialThe combined ethyl acetate phases are dried over sodium sulfate
  9. customevaporated
  10. stirringThe thus-obtained material is stirred at 130° for 6 hours with 10 ml of acetic anhydride and 1 ml of pyridine
  11. customThe mixture is evaporated
  12. customthe residue is partitioned between ice-water and methylene chloride
  13. dry with materialThe methylene chloride phase is dried over sodium sulfate
  14. customevaporated
  15. customthe residue is chromatographed on 30 g of silica gel with methylene chloride
  16. dissolutionThe thus-obtained diacetate is dissolved in 10 ml of methanol
  17. additionThe solution is treated with 4.2 ml of 1N sodium hydroxide solution
  18. stirringstirred at 0° for 1 hour
  19. customevaporated
  20. custompartitioned between ethyl acetate and saturated sodium chloride solution
  21. dry with materialThe ethyl acetate phases are dried over sodium sulfate
  22. customevaporated
  23. customthe residue is recrystallized from methylene chloride

Sources & evidence

ORD record
ord-2a2949f325cb410a969a2db7369cd705
Source dataset
uspto-grants-1993_08
Patent number
US05236952

Reaction notes

Loading…