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

Participants

Reaction Steps

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 (4.246 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 in the next step without further purification.

Provenance & Evidence