Certain 3,4-disubstituted phenols and pharmaceutically acceptable salts thereof are provided which mimic IL-1 activity by inducing IL-2 synthesis and subsequent IL-2 receptor expression. Specifically, the invention provides compounds of Formula I and acid addition salts thereof: ##STR1## wherein Y is ##STR2## NHSO.sub.2 or SO.sub.2 NH where R.sup.4 is H; Z is --O--, --NH--, --NR--, --S--, or other heteroatoms capable of hydrogen bonding with R.sup.4 to give a preferred conformation;R is alkyl;R.sup.1 is --OH;R.sup.2 is H, alkyl, cycloalkyl, aralkyl, substituted or unsubstituted aryl, or a substituted or unsubstituted nitrogen heterocyclic group having 4 to 5 nuclear carbon atoms; andR.sup.3 is a lipophilic moiety selected from the group consisting of substituted C.sub.1 -C.sub.10 alkyl, C.sub.3 -C.sub.16 cycloalkyl and 2,4-di-t-pentylphenyl.