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Synthesis and Conformational Analysis of N-Azulenyl-N-methyl Amides: Influence of Coplanarity on Amide Conformational
Ai Ito1, Ai Tsuchida1, Mari Arakawa1
1Showa Pharmaceutical University, 3-2-1 Higashi-Tamagawagakuen, Machida, Tokyo 194-8543, Japan.
Abstract:
We synthesized a series of N-azulenyl-N-methylamides and investigated their conformational preferences in solution and in the solid state. N-(1-Azulenyl)-N-methyl amides 12 and N-(6-azulenyl)-N-methyl amides 14 adopt the cis form almost exclusively in solution and in the crystal state, like general N-methyl aromatic amides such as N-methylbenzanilide and N-methylacetanilide. However, N-(2-azulenyl)-N-methyl amides 13 exhibit high ratios of the trans form in solution and adopt the trans form in the solid state due to the high degree of coplanarity of the 2-azulenyl moiety and the amide plane.
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