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

HRID 428826

Reaction equation

HRID 428826 reaction equation
[Cl:1][C:2]1[C:3]([OH:12])=[C:4]([O:10]C)[CH:5]=[C:6]([CH:9]=1)[CH:7]=[O:8].B(Br)(Br)Br>ClCCl>[Cl:1][C:2]1[CH:9]=[C:6]([CH:5]=[C:4]([OH:10])[C:3]=1[OH:12])[CH:7]=[O:8]

Participants

4

Reactant 2

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

Product 1

HCID 24681823-Chloro-4,5-dihydroxybenzaldehydeYield 77.3%

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent2×

Conditions

Temperature
0 °C

Procedure

37.2 g of commercial 5-chloro vanillin and 800 ml of dichloromethane were mixed together under nitrogen and cooled to 0° C. 300 ml of a molar solution of boron tribromide in dichloromethane are added and the mixture stood for one night at ambient temperature. It was concentrated, cooled again to 0° C. and acidified. The crystallized product was separated, washed with water, dried and crystallized from an isopropanol—water mixture (1-2 by volume) to obtain 26.6 g of the expected product melting at >260° C.

Workup

  1. waitthe mixture stood for one night at ambient temperature
  2. concentrationIt was concentrated
  3. temperaturecooled again to 0° C.
  4. customThe crystallized product was separated
  5. washwashed with water
  6. customdried
  7. customcrystallized from an isopropanol—water mixture (1-2 by volume)

Sources & evidence

ORD record
ord-1629714fd8b945d083be2677196e446f
Source dataset
uspto-grants-2001_11
Patent number
US06313305B1

Linked notes

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