Boron tribromide → 3-Chloro-4,5-dihydroxybenzaldehyde

HRID 1024484Notes

Reaction equation

HRID 1024484 reaction equation
[Cl:1][C:2]1[CH:3]=[C:4]([CH:7]=[C:8]([O:11]C)[C:9]=1[OH:10])[CH:5]=[O:6].B(Br)(Br)Br>ClCCl>[Cl:1][C:2]1[CH:3]=[C:4]([CH:7]=[C:8]([OH:11])[C:9]=1[OH:10])[CH:5]=[O:6]

Participants

4

Reactant 2

HCID 25134Boron tribromideHCID 296223-Chloro-4-hydroxy-5-methoxybenzaldehyde

Product 1

HCID 24681823-Chloro-4,5-dihydroxybenzaldehydeYield 109.3%

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent2×

Procedure

A solution of 19.1 g 3-chloro-4-hydroxy-5-methoxy benzaldehyde in dichloromethane (1600 ml) was cooled in ice water bath. Boron tribromide (53.8 g) in dichloromethane (80 ml) were added and the mixture was stirred for two hours at ambient temperature and then was concentrated. The residue was cooled again with ice water bath and precipitated with ice-cold aqueous hydrochloric acid (1N, 500 ml). Solid residue was received upon filtration, then washed with ice water (500 ml) and dried in the air to obtain 19.3 g crude product of 3-chloro-4,5-dihydroxy benzaldehyde, which was used for the following step.

Workup

  1. concentrationwas concentrated
  2. temperatureThe residue was cooled again with ice water bath
  3. customprecipitated with ice-cold aqueous hydrochloric acid (1N, 500 ml)
  4. filtrationSolid residue was received upon filtration
  5. washwashed with ice water (500 ml)
  6. customdried in the air

Sources & evidence

ORD record
ord-3b4c950f55874c7fa4c8f77d604476d2
Source dataset
uspto-grants-2014_05
Patent number
US08722896B2

Reaction notes

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