Hydrochloric Acid → 2-Iodo-4-methoxybenzoic acid

HRID 1458736Notes

Reaction equation

HRID 1458736 reaction equation
[CH3:1][O:2][C:3]1[CH:4]=[C:5](N)[C:6](=[CH:10][CH:11]=1)[C:7]([OH:9])=[O:8].Cl.N([O-])=O.[Na+].[I-:18].[K+].OS(O)(=O)=O.II>O.C1(C)C=CC=CC=1>[I:18][C:5]1[CH:4]=[C:3]([O:2][CH3:1])[CH:11]=[CH:10][C:6]=1[C:7]([OH:9])=[O:8]

Participants

9

Reactant 6

HCID 313Hydrochloric AcidHCID 807IodineHCID 1118Sulfuric AcidHCID 4875Potassium IodideHCID 3510102-Amino-4-methoxybenzoic acidHCID 23668193Sodium Nitrite

Product 1

HCID 128221822-Iodo-4-methoxybenzoic acidYield 52%

Reagents, catalysts & solvents 2

HCID 962WaterSolvent3×HCID 1140TolueneSolvent

Conditions

Temperature
75 °C

Procedure

A mixture of 4-methoxyanthranilic acid (30.5 g, 0.18 mol), water (274.5 ml), and concentrated HCl (36.6 ml) is heated at 75° C. to effect solution and then is cooled to 0° C. The mixture is then treated with NaNO2 (13.3 g) in water (27.5 ml), followed by potassium iodide (45.75 g) in a water (75 ml)/H2SO4 (10.1 ml) solution. The reaction mixture is heated on a steam bath for 2 hours, then excess iodine is steam distilled. The reaction mixture is then cooled, and the product is collected by filtration and dried in an oven at 75° C. to afford 39.28 g (78.6%) of crude product. The crude product is treated with toluene, the mixture is filtered, and the filtrate is concentrated to afford 26.03 g of 2-iodo-4-methoxybenzoic acid.

Workup

  1. temperatureis cooled to 0° C
  2. temperatureThe reaction mixture is heated on a steam bath for 2 hours
  3. distillationdistilled
  4. temperatureThe reaction mixture is then cooled
  5. filtrationthe product is collected by filtration
  6. customdried in an oven at 75° C.
  7. customto afford 39.28 g (78.6%) of crude product
  8. filtrationthe mixture is filtered
  9. concentrationthe filtrate is concentrated

Sources & evidence

ORD record
ord-57c6be32e4c845c283f077d232cf9339
Source dataset
uspto-grants-1998_12
Patent number
US05852035

Reaction notes

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