We first examined derivatization of the aromatic ring of isoproterenol (I). Direct substitution on the ring, however, in most cases eliminated@-adrenergic activity, making this approach unattractive for attachment to carriers. l% b Substitution by an ether linkage to the benzylic hydroxyl has been reported to result in the loss of activity! When we prepared and rigorously purified the P-ethyl ether derivative of isoproterenol, we also observed virtually complete ...
