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Walczynski K, Zuiderveld OP, Timmerman H: Non-imidazole histamine H3 ligands. Eur J Med Chem. 2005 Jan;40(1):15-23.
Part III. New 4-n-propylpiperazines as non-imidazole histamine H3-antagonists.. In search for a new lead of non-imidazole histamine H3-receptor antagonists, a series of 1 [(2-thiazolopyridine)-4-n-propyl] piperazines, the analogous 1-[(2-oxazolopyridine)-4-npropyl] piperazines, 1-[(2-benzothiazole)-4-n-propyl] piperazine and 1-[(2-benzooxazole) 4-n-propyl] piperazine were prepared and in vitro tested as H3-receptor antagonists (the electrically evoked contraction of the guinea-pig jejunum). It appeared that by comparison of homologous pairs the thiazolo derivatives have slightly higher activity than their oxazolo analogues. The most potent compound of these series is the 1-(2-thiazolo [4,5-c] pyridine)-4-n-propylpiperazine (3c) with pA2 = 7.25 (its oxazole analogue (4g) showed pA2 = 6.9). The structure-activity relationships for compounds with various positions of the nitrogen in the benzene ring for the thiazoles compared with oxazoles are discussed. |
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