1-alkyl-4-acylpiperazines as a new class of imidazole-free histamine H3 receptor antagonists

With the aim of identifying structurally novel, centrally acting histamine H-3 antagonists, arrays of monoacyldiamines were screened. This led to the discovery of a series of 1-alkyl-4-acylpiperazines which were potent antagonists at the human histamine H-3 receptor. The most potent amides had antagonist potencies in the subnanomolar range.