Structural study of the acylation products of persubstituted para-nitrosophenols

Acylation of potassium 2,6-di(alkoxycarbonyl)-3,5-dimethyl-4-nitrosophenolate with acetic anhydride and benzoyl chloride gave previously unknown 10 derived acyl compounds. 1H NMR spectroscopy and X-ray diffraction data have been used to show that the oxygen atom of the nitroso group undergoes acylation to form the quinoid products. X-ray powder crystal structure analysis of 1-acetoxymino-3,5-di(methoxycarbonyl)-2,6-dimethyl-1,4-benzoquinone, 1-acetoxymino-3,5-di(ethoxycarbonyl)-2,6-dimethyl-1,4-benzoquinone and 1-benzoyloxymino-3,5-di(propoxycarbonyl)-2,6-dimethyl-1,4-benzoquinon revealed a planar structure of the molecules with quinoid ring as the central moiety. Alkyloxycarbonyl groups rotate in the range 94-101° relative to the plane of the molecule. Typical hydrogen bonds are absent. Molecules fill the unit cell following the closest packing principle in the form of the columns. The 1H NMR spectroscopic data indicates that the direction of acylation and type of structure for the other members of the series of the studied compounds are the same.