Boron tribromide → 3,4-Dihydroxy-5-nitrobenzaldehyde

HRID 963786Notes

Reaction equation

HRID 963786 reaction equation
[N+:1]([C:4]1[C:5]([OH:14])=[C:6]([O:12]C)[CH:7]=[C:8]([CH:11]=1)[CH:9]=[O:10])([O-:3])=[O:2].B(Br)(Br)Br>ClCCl>[N+:1]([C:4]1[CH:11]=[C:8]([CH:7]=[C:6]([OH:12])[C:5]=1[OH:14])[CH:9]=[O:10])([O-:3])=[O:2]

Participants

4

Reactant 2

HCID 25134Boron tribromideHCID 811345-Nitrovanillin

Product 1

HCID 57489573,4-Dihydroxy-5-nitrobenzaldehydeYield 55.4%

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent2×

Conditions

Temperature
0 °C

Procedure

35 g of 5-nitro vanillin (commercial) and 1200 ml of dichloromethane were mixed together under nitrogen and the mixture was cooled to 0° C. 533 ml of a molar solution of boron tribromide in dichloromethane were added and the mixture stood for 2 days at ambient temperature and then was concentrated. The residue was taken up cold (ice bath+methanol) in 300 ml of 2N hydrochloric acid and the mixture was stirred for two to three hours at this temperature, then left for 16 hours at ambient temperature. Extraction was carried out with ethyl acetate and the organic phase was washed, dried and concentrated to obtain 18 g of the expected product melting at>260° C.

Workup

  1. concentrationwas concentrated
  2. waitleft for 16 hours at ambient temperature
  3. extractionExtraction
  4. washthe organic phase was washed
  5. customdried
  6. concentrationconcentrated

Sources & evidence

ORD record
ord-2062bd895b2541cd8183c7b2e94e6dc9
Source dataset
uspto-grants-1998_06
Patent number
US05763617

Reaction notes

Loading…