| Summary: | The stereochemical properties of <i>N</i>-acyl-5<i>H</i>-dibenzo[<i>b</i>,<i>d</i>]azepin-7(6<i>H</i>)-ones (<b>2a</b>–<b>c</b>), which inhibit potassium channels in T cells, were examined by freezing their conformational change due to 4-methyl substitution. <i>N</i>-Acyl-5<i>H</i>-dibenzo[<i>b</i>,<i>d</i>]azepin-7(6<i>H</i>)-ones exist as pairs of enantiomers [(a<sup>1</sup><i>R</i>, a<sup>2</sup><i>R</i>), (a<sup>1</sup><i>S</i>, a<sup>2</sup><i>S</i>)], and each atropisomer is separable at room temperature. An alternate procedure for preparing 5<i>H</i>-dibenzo[<i>b</i>,<i>d</i>]azepin-7(6<i>H</i>)-ones involves the intramolecular Friedel–Crafts cyclization of <i>N</i>-benzyloxycarbonylated biaryl amino acids. Consequently, the <i>N</i>-benzyloxy group was removed during the cyclization reaction to produce 5<i>H</i>-dibenzo[<i>b</i>,<i>d</i>]azepin-7(6<i>H</i>)-ones suitable for the subsequent <i>N</i>-acylation reaction.
|
|---|