Non-imidazole histamine H-3 ligands. Part I. Synthesis of 2-(1-piperazinyl)- and 2-(hexahydro-1H-1,4-diazepin-1-yl)benzothiazole derivatives as H-3-antagonists with H-1 blocking activities
K. Walczynski et al., Non-imidazole histamine H-3 ligands. Part I. Synthesis of 2-(1-piperazinyl)- and 2-(hexahydro-1H-1,4-diazepin-1-yl)benzothiazole derivatives as H-3-antagonists with H-1 blocking activities, FARMACO, 54(10), 1999, pp. 684-694
New 2-(1-Piperazinyl)- and 2-(hexahydro-1H-1,4-diazepin-1-yl)benzothiazoles
were prepared and tested as H-1- and H-3-receptor antagonists. A number of
compounds showed weak H-1-antagonistic activity, with pA(2) values ranging
from 5.5 to 6.1. The simple alkyl substituted, 2-[1-(4-methyl and 4-ethyl)
piperazinyl] analogues show increasing, moderate I-I,-antagonistic activity
(pA(2) = 6.0, and pA(2) = 7.0). The compounds with 4-phenylalkyl substitut
ion, for both the piperazinyl and the hexahydro-1H-1,4-diazepin-1-yl homolo
gues series, regardless of the different physicochemical properties of the
pm a substituents at the phenyl ring, showed weak H-3-antagonistic activity
with pA(2) values ranging from 4.4 to 5.6. (C) 1999 Elsevier Science S.A.
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