Ethanol → Ethyl(3,4-dihydroxy-5-nitrobenzoyl)acetate

HRID 725381Notes

Reaction equation

HRID 725381 reaction equation
C[O:2][C:3]1[CH:4]=[C:5]([CH:19]=[C:20]([N+:24]([O-:26])=[O:25])[C:21]=1[O:22]C)[C:6]([CH:8](C(OCC)=O)[C:9]([O:11][CH2:12][CH3:13])=[O:10])=[O:7].B(Br)(Br)Br.C(O)C>C(Cl)Cl>[OH:2][C:3]1[CH:4]=[C:5]([CH:19]=[C:20]([N+:24]([O-:26])=[O:25])[C:21]=1[OH:22])[C:6]([CH2:8][C:9]([O:11][CH2:12][CH3:13])=[O:10])=[O:7]

Participants

5

Reactant 3

HCID 702EthanolHCID 25134Boron tribromideHCID 19000155Diethyl 3,4-dimethoxy-5-nitrobenzoylmalonate

Product 1

HCID 21459116Ethyl(3,4-dihydroxy-5-nitrobenzoyl)acetate

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent2×

Procedure

20.1 g of diethyl (3,4-dimethoxy-5-nitrobenzoyl)malonate are dissolved in 200 ml of methylene chloride, whereupon the solution is cooled to -20° and at this temperature there is added dropwise while stirring within 15 minutes a solution of 68.1 g of boron tribromide in 120 ml of methylene chloride. The mixture is subsequently stirred at room temperature overnight. After cooling to -20°, the mixture is treated with 300 ml of ethanol and stirred at room temperature for 30 minutes. The solvent is distilled in a water-jet vacuum at 40°. The residue is treated with 300 ml of ice-water and methylene chloride, The organic phase is washed with water, dried over sodium sulfate and evaporated. The crude product obtained is chromatographed on a 10-fold amount of silica gel with toluene. After crystallization from methylene chloride/hexane there is obtained ethyl (3,4-dihydroxy-5-nitrobenzoyl)acetate in the form of yellow crystals of m.p. 136°-137°.

Workup

  1. temperatureis cooled to -20° and at this temperature there
  2. additionis added dropwise
  3. temperatureAfter cooling to -20°
  4. stirringstirred at room temperature for 30 minutes
  5. distillationThe solvent is distilled in a water-jet vacuum at 40°
  6. additionThe residue is treated with 300 ml of ice-water and methylene chloride
  7. washThe organic phase is washed with water
  8. dry with materialdried over sodium sulfate
  9. customevaporated
  10. customThe crude product obtained
  11. customis chromatographed on a 10-fold amount of silica gel with toluene
  12. customAfter crystallization from methylene chloride/hexane there

Sources & evidence

ORD record
ord-10e33da63ce14f8db6498d1bddc06584
Source dataset
uspto-grants-1998_01
Patent number
US05705703

Reaction notes

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