W. Soudijn, I. Wijngaarden, A. Knaeps
1978
Citations
0
Influential Citations
2
Citations
Journal
Journal of Labelled Compounds and Radiopharmaceuticals
Abstract
The reaction conditions for the preparation of amides from labelled carboxylic acids and amines using EEDQ (2-ethoxy-1 (2H)-quinolinecarboxylic acid, ethyl ester) as a reagent were modified for the synthesis of the tritium labelled benzamide Halopemide (N-{2-[4-(5-chloro-2,3-dihydro-2-oxo- lH-benzimidazol-1-yl)-1-piperidinyl] ethyl} −4-fluorobenzamide), as EEDQ, reacted in an unexpected way, resulting in a 1:1 mixture of the benzamide and the N-carbethoxy derivative of the starting amine and of “unreacted” carboxylic acid. The basicity of the starting amine influenced the yield of the benzamide. By optimalizing the reaction conditions, it was possible to convert the labelled benzoic acid quantitatively into the benzamide.