Water → Phenol

Participants

Reaction Steps

Polish patent No. 99,682 (CA 91, 107,806) has disclosed that anhydrous phenolsulfonic acid can be obtained from phenol and sulfuric acid if the water of reaction, formed during the reaction, is removed from the reaction medium. This is effected by sulfonating phenol with H2SO4 and dripping the sulfonation mixture through a column with a heating jacket, in which a counter-current gas stream of an inert organic solvent, for example C7H16, azeotropically removes the water of reaction. The disadvantages of this process are the expense for equipment and the expensive separation of the organic solvent from the reaction product. According to Ind. eng. Chem. 32, 408 (1940), the water of reaction can also be removed by addition of BF3 to the reaction mixture, by distillation in the form of BF3. 2 H2O, but the BF3 must then be recovered via Ca(BF4)2 in a downstream stage.

Provenance & Evidence