Hydrochloric Acid → 2-Iodo-4-methoxybenzoic acid

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Reaction Steps

150 G. of 4-methoxy-anthranilic acid are suspended at 0° C. in 2 liters of water and 80 ml. of concentrated hydrochloric acid. To this solution is added dropwise with stirring at 0°-5° C. over a period of 30 minutes a solution of 62 g. of sodium nitrite in 130 ml. of water. The resulting diazonium salt solution is stirred for an additional 15 minutes at 0°-5° C. A solution of 164 g. of potassium iodide in 700 ml. of 5-N sulfuric acid is subsequently added dropwise at 3°-6° C. over a period of 45 minutes. Then, the mixture is stirred at room temperature for 30 minutes and heated slowly to reflux. After boiling at reflux for 2 hours, the mixture is cooled to room temperature. The precipitated brown crystals are removed by filtration and washed neutral with water. The filter cake is dried under reduced pressure, and there is obtained 2-iodo-4-methoxy-benzoic acid as brown crystals having a melting point of 174° C.

Provenance & Evidence