Acylated and alkylated histamine derivatives as new histamine H3-receptor antagonists
摘要:
New histamine H-3-receptor antagonists were prepared and investigated for their ability to increase synthesis and release of histamine mediated by inhibition of presynaptically located H-3-receptors. Acyl derivatives of histamine methylated at different positions show poor activity at H-3-receptors, whereas N-alpha-alkyl and particularly N-alpha-acyl derivatives of histamine possess moderate to good H-3-receptor antagonist activity. A not-too-bulky and lipophilic residue in an optimal distance of 3-4 methylene groups from the amide function leads to potent and selective H-3-receptor antagonists. N-alpha-Histamine-gamma-phenylbutyramide 11 and N-alpha-histamine-gamma-cyclohexylbutyramide 13 are H-3-receptor antagonists with -log K-i of 7.1 and 7.3, respectively. Structure-activity relationships of different substitution patterns are discussed.
3-Acyl-1,3-diaryltriazenes as neutral and selective acylating agents
摘要:
New 3-acyl-1,3-diaryltriazenes have been prepared and their reactions with amino compounds have been studied. Reactions proceed rapidly under mild conditions to give the corresponding N-acyl products: Reagents enable chemoselective acylation of aliphatic primary and secondary amines in the presence of other acylable functional groups. (C) 2001 Elsevier Science Ltd. All rights reserved.