2-acetamido-N-benzyl-2-(methoxyamino)acetamides: functionalized amino acid anticonvulsants

In the crystal structure of 2-acetamido-N-benzyl-2-(methoxyamino)acetamide (3L), C12H17N3O3, the 2-acetylaminoacetamide moiety has a linearly extended conformation, with an interplanar angle between the two amide groups of 157.3 (1) degrees . In 2-acetamido-N-benzyl-2-[methoxy(methyl)amino]acetamide (3N), C13H19N3O3, the planes of the two amide groups intersect at an angle of 126.4 (4) degrees , resulting in a chain that is slightly more bent. The replacement of the methoxyamino H atom of 3L with a methyl group to form 3N and concomitant loss of hydrogen bonding results in some positional/thermal disorder in the methoxy(methyl)amino group. In both structures, in addition to classical N-H...O hydrogen bonds, there are also weak non-standard C-H...O hydrogen bonds. The hydrogen bonds and packing interactions result in planar hydrophilic and hydrophobic areas perpendicular to the c axis in 3L and parallel to the ab plane in the N-methyl derivative. Stereochemical comparisons with phenytoin have identified two O atoms and a phenyl group as molecular features likely to be responsible for the anticonvulsant activities of these compounds.