EFFICIENCY OF SUBSTITUTED PHENOLS IN PHENOL - SULFURIC-ACID REACTION

2,6-Dimethyl phenol, 2,3, 6-trimethyl phenol and 2, 5-dimethyl phenol which yielded pinkish orange condensation products with hydroxymethyl furaldehyde in 75% sulfuric acid were found to be better prochromogens than phenol. The relative epsilon values for the products derived fro m the four phenols were found to be 55400, 45400, 47000 and 36500. 2,4 -Dimethyl phenol which could yield only an o-semiquinonoid type of chr omogen, was less efficient (epsilon, 22800). Both o- and p-substituted condensation products with these phenols absorbed maximally around 50 5-510 nm. 3,4-Dimethyl phenol, 3,4,5-trimethyl phenol, 3,5-dimethyl ph enol and 2,3,5-trimethyl phenol were less efficient than phenol in phe nol-sulfuric acid reaction as prochromogens. The condensation products of hydroxymethyl furaldehyde with 3,4-dimethyl phenol and 3,4,5-trime thyl phenol, yielded isomers in each instance, differing in absorption maxima by 90-100 nm. Broad spectral patterns of condensation products arising from 3,5-dimethyl phenol and 2,3,5-trimethyl phenol suggest t he formation of isomeric chromogens, also with these compounds.