79278-73-2

Upstream product

• 75970-51-3 1-methyl-N-(4-piperidinyl)-1H-benzimidazol-2-amine dihydrobromide 
• 73733-81-0 ethyl 4-{[(2-aminophenyl)aminothioxomethyl]amino}-1-piperidinecarboxylate 
• 73788-44-0 ethyl 4-<(1-methyl-1H-benzimidazol-2-yl)amino>-1-piperidinecarboxylate 
• 73734-07-3 (1H-benzimidazol-2-yl)-(1-ethoxycarbonyl-piperidin-4-yl)amine 
• 73733-70-7 ethyl 4-isothiocyanato-1-piperidinecarboxylate 
• 58859-46-4 ethyl 4-aminopiperidine-1-carboxylate 

Relevant academic research and scientific papers

New antihistaminic N-heterocyclic 4-piperidinamines. 1. Synthesis and antihistaminic activity of N-(4-piperidinyl)-1H-benzimidazol-2-amines

The synthesis of a series N-(4-piperidinyl)-1H-benzimidazol-2-amines and the preliminary evaluation of their in vitro and in vivo antihistaminic activity are described. Cyclodesulfurization of (2-aminophenyl) thioureas with mercury(II) oxide resulted in 2-aminobenzimidazole intermediates, which were monoalkylated on the endo-nitrogen atom. After deprotection of the piperideine nitrogen atom with 48% aqueous hydrobromic acid solution, the title compounds were obtained by three different methods, viz. alkylation, reductive amination, or oxirane ring-opening reactions. The in vivo antihistaminic activity was evaluated by the compound 48/80 induced lethality test in rats and histamine-induced lethality test in guinea pigs after oral and/or subcutaneous administration. The duration of action, for a selected number of compounds, was studied in the guinea pig. The phenylethyl derivatives showed the most potent antihistamine properties after oral administration in both animal species.