Phenolate Sodium → 4-Hydroxybenzoic Acid

Participants

Reaction Steps

In contrast to published information, it has been found that the degree of conversion of sodium phenolate to sodium salicylate is practically independent of the reaction temperature. At 165° C. and at 200° C., 85-88% conversion is easily obtained, but by-product formation is reduced as the temperature is increased. For instance, reaction at 140°-150° C. gives about 9% non-salicylic acids mostly 4-HBA in the crude product mixture whereas reaction at 190°-195° C. (at 5 bar co-pressure) gives less than 0.5% non-salicylic acids in the reaction product mixture.

Provenance & Evidence