p-Toluenesulfonic acid → Methyl 3-bromo-2-fluorobenzoate

HRID 852505Notes

Reaction equation

HRID 852505 reaction equation
[Br:1][C:2]1[C:3]([F:11])=[C:4]([CH:8]=[CH:9][CH:10]=1)[C:5]([OH:7])=[O:6].[CH3:12]OC(OC)OC.C1(C)C=CC(S(O)(=O)=O)=CC=1>CO>[Br:1][C:2]1[C:3]([F:11])=[C:4]([CH:8]=[CH:9][CH:10]=1)[C:5]([O:7][CH3:12])=[O:6]

Participants

5

Reactant 3

HCID 6101p-Toluenesulfonic acidHCID 9005Trimethyl orthoformateHCID 27363133-Bromo-2-fluorobenzoic acid

Product 1

HCID 21584505Methyl 3-bromo-2-fluorobenzoateYield 84%

Reagents, catalysts & solvents 1

HCID 887MethanolSolvent

Procedure

A solution of 3-bromo-2-fluorobenzoic acid (0.219 g, 1 mmol) in dry methanol (5 ml) under nitrogen was treated with trimethylorthoformate (0.22 ml, 2 mmol) and p-toluenesulfonic acid (catalytic amount), and then heated under reflux. After 16 h, the mixture was evaporated and the residue partitioned between water and Et2O. The organic layer was washed with sat. sodium hydrogen carbonate solution, water, brine, dried (MgSO4) and evaporated to give methyl 3-bromo-2-fluorobenzoate (0.195 g, 0.84 mmol, 84%): 1H NMR (CDCl3) δ 7.90-7.85 (m, 1H), 7.71-7.65 (m, 1H), 7.10 (dt, 1H, J=8.0, 1.0 Hz) and 3.94 (s, 3H): MS (EI) 232 (M+).

Workup

  1. temperatureheated
  2. temperatureunder reflux
  3. customthe mixture was evaporated
  4. customthe residue partitioned between water and Et2O
  5. washThe organic layer was washed with sat. sodium hydrogen carbonate solution, water, brine
  6. dry with materialdried (MgSO4)
  7. customevaporated

Sources & evidence

ORD record
ord-ffe7ab71f2774a8bad0f83c11138a5c3
Source dataset
uspto-grants-2007_08
Patent number
US07253203B2

Reaction notes

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