A compound of the formula ##STR00001## where R.sup.1 is H, C.sub.1 C.sub.4 alkyl and OH; R.sup.2 in is H, C.sub.1 C.sub.4 alkyl and OH; R.sup.3 is H and C.sub.1 C.sub.4 alkyl; R.sup.4 is H and C.sub.1 C.sub.4 alkyl; n is an integer between 0 and 2 inclusive; R.sup.5 is a nullity, NHR.sup.7C(O)--, C.sub.6H.sub.4--, C.sub.6H.sub.4--O--; R.sup.7 is C.sub.2 C.sub.6 alkyl; and R.sup.6 is a moiety capable of crossing the blood brain barrier and is as a free compound serotonin, dopamine, blood brain barrier (BBB) peptide, membrane translocating peptide, TAT peptides, bradykinin, beta-endorphin, bombesin, calcitonin, cholecystokinin, an enkephalin, dynorphin, insulin, gastrin, substance P, neurotensin, glucagon, secretin, somatostatin, motilin, vasopressin, oxytocin, prolactin, thyrotropin, an angiotensin, galanin, neuropeptide Y, thyrotropin-releasing hormone, gonadotropnin-releasing hormone, growth hormone-releasing hormone, luteinizing hormone, vasoactive intestinal peptidegluconate, transferrin, glucosylamine, amino saccharin, saccharin ester, lactylamine, leucine, tryptophan, amino glutamate and amino cholines.