SYNTHESES OF LIQUID-CRYSTAL INTERMEDIATES 4-ALKYLBENZENETHIOLS AND PHENOLS

An improved synthesis of 4-alkylbenzenethiols was developed. Sulfonation of alkylbenzenes in sulfuric acid at 75 degree yields 4-akylbenzene sulfonic acid salts which are free of other positional isomers in high yields. Conversion to the thiols via the sulfonyl chlorides provide a high yield, 3 step synthesis of pure 4-alkylbenzenethiols. Fusion of the salts with potassium hydroxide provides a simple synthetic approach to pure 4-alkylphenols as well. Both the thiols and phenols are useful intermediates in the preparation of mesomorphic compounds.