Sulfuric Acid → Methyl 5-bromo-2,4-dihydroxybenzoate

HRID 1927695Notes

Reaction equation

HRID 1927695 reaction equation
[Br:1][C:2]1[C:3]([OH:12])=[CH:4][C:5]([OH:11])=[C:6]([CH:10]=1)[C:7]([OH:9])=[O:8].S(=O)(=O)(O)O.[C:18](=O)([O-])O.[Na+]>CO.O>[Br:1][C:2]1[C:3]([OH:12])=[CH:4][C:5]([OH:11])=[C:6]([CH:10]=1)[C:7]([O:9][CH3:18])=[O:8]

Participants

6

Reactant 3

HCID 1118Sulfuric Acid2×HCID 818145-Bromo-2,4-dihydroxybenzoic acidHCID 516892Sodium Bicarbonate

Product 1

HCID 44828918Methyl 5-bromo-2,4-dihydroxybenzoateYield 83.4%

Reagents, catalysts & solvents 2

HCID 887MethanolSolventHCID 962WaterSolvent

Conditions

Temperature
55 °C

Procedure

8.9 kg of 5-bromo-2,4-dihydroxybenzoic acid are dissolved in 70 l of methanol and heated to 55° C. 800 ml of sulfuric acid (w=95-98%) are subsequently metered in, and the mixture is stirred under gentle reflux for 4 days, during which a further 500 ml of sulfuric acid (w=95-98%) were added daily (3 times). The reaction mixture is stirred into a cooled solution (5° C.) of 9 kg of sodium hydrogencarbonate in 100 l of water. Filtration and drying in vacuo at 50° C. gives 7.87 kg (83%) of methyl 5-bromo-2,4-dihydroxybenzoate (white crystals), MW 247.1.

Workup

  1. additionwere added daily (3 times)
  2. filtrationFiltration
  3. customdrying in vacuo at 50° C.

Sources & evidence

ORD record
ord-0fae634ea35b4d76af4c8b6f5e129b9e
Source dataset
uspto-grants-2012_05
Patent number
US08183279B2

Reaction notes

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