Iodine → 5-Chloro-4-iodo-2-methoxybenzoic acid

HRID 2184454Notes

Reaction equation

HRID 2184454 reaction equation
N[C:2]1[C:10]([Cl:11])=[CH:9][C:5]([C:6]([OH:8])=[O:7])=[C:4]([O:12][CH3:13])[CH:3]=1.N([O-])=O.[Na+].[I-:18].[K+].II>O.S(=O)(=O)(O)O>[I:18][C:2]1[C:10]([Cl:11])=[CH:9][C:5]([C:6]([OH:8])=[O:7])=[C:4]([O:12][CH3:13])[CH:3]=1

Participants

7

Reactant 4

HCID 807IodineHCID 4875Potassium IodideHCID 816264-Amino-5-chloro-2-methoxybenzoic acidHCID 23668193Sodium Nitrite

Product 1

HCID 167918585-Chloro-4-iodo-2-methoxybenzoic acidYield 59.6%

Reagents, catalysts & solvents 2

HCID 962WaterSolvent3×HCID 1118Sulfuric AcidSolvent

Procedure

A stirred solution of 4-amino-5-chloro-2-methoxy benzoic acid (12.25 g , 60.8 mmol) in water (136 mL ) and concentrated sulfuric acid (34 mL) was cooled to 0° C. in a flask fitted with an overhead stirrer. A solution of sodium nitrite (4.62 g , 66.9 mmol) in water (26 mL) was added dropwise while keeping the internal temperature around 0° C. Potassium iodide (11.11 g, 66.9 mmol) and iodine (4.24 g, 33.5 mmol) were dissolved in water (130 mL) and added dropwise to the stirred reaction mixture. After 2 hours the reaction was extracted with ethyl acetate. The organic extracts were then washed with 10% sodium thiosulfate and brine, then dried over magnesium sulfate, filtered and evaporated to dryness to yield 11.32 g of the title compound, m.p. 150°-151° C. This material was used without further purification.

Workup

  1. customfitted with an overhead stirrer
  2. customthe internal temperature around 0° C
  3. additionadded dropwise to the stirred reaction mixture
  4. extractionAfter 2 hours the reaction was extracted with ethyl acetate
  5. washThe organic extracts were then washed with 10% sodium thiosulfate and brine
  6. dry with materialdried over magnesium sulfate
  7. filtrationfiltered
  8. customevaporated to dryness

Sources & evidence

ORD record
ord-473955026c7042859d944aa42143c39d
Source dataset
uspto-grants-2005_05
Patent number
US06900200B2

Reaction notes

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