Nitro derivatives of glutethimide

Crystallographic experiments performed on single crystals of m-nitrogluteth imide [3-ethyl-3-(3'-nitrophenyl)piperidine-2,6-dione, C13H14N2O4], (I), an d o,p-dinitroglutethimide [3-ethyl-3-(2',4'-dinitrophenyl)piperidine-2,6-di one, C13H13N3O6], (II), have unambiguously confirmed the molecular structur es. From HPLC data it has been found that both of the title compounds are b y-products in the nitration of glutethimide. The six-membered glutarimide r ings of (I) and (II) have an envelope conformation with the C4 atom out of the plane, i.e, with C4-exo puckering in (I), but with C4-endo puckering in (II). Steric hindrances are, most likely, responsible for the observed con formational dissimilarity. The molecular structure of compound (I), unlike compound (II), is very similar to that of aminoglutethimide. Enantiomeric m olecules in both compounds are linked together through pairs of symmetric R -2(2)(8) intermolecular hydrogen bonds forming centrosymmetric racemic dime rs.