Spirotetrahydronaphthalene analogues of sympathomimetic catecholamines. Synthesis and adrenergic activity of 5,6- and 6,7-dihydroxy-3,4-dihydrospiro(naphtalen-1(2H)-3'-piperidines)

The 5,6- (5a) and 6,7-dihydroxy-3,4-dihydrospiro[naphthalen-1(2H)-3« -piperidine] (6a) and their N-isopropyl derivatives (5b and 6b), DDSNPs, were synthesized. These compounds can be viewed as the result of the combination of the structure of the 3-(3,4-dihydroxyphenyl)- piperidine 2a or 2b, with the structure of the corresponding 1-(aminomethyl)-5,6-dihydroxy- (3a or 3b) or 1-(aminomethyl)-6,7-dihydroxy-1,2,3,4-tetrahydronaphthalene (4a or 4b), 1-AMDTNs. The new compounds (5a, b and 6a, b) were assayed for their a and b adrenergic properties by means of binding experiments and functional tests and the results were compared with those obtained for catecholamines 1a, b and the previously described 3-(3,4- dihydroxyphenyl)piperidine (3-DPP; 2) and 1-AMDTNs (3, 4). Comparison of the afŽ nity and activity data of novel derivativeswith those of reference compounds 2, 3 and 4 shows a general low ability of DDSNPs 5 and 6 to interact with both a and b - adrenoceptors