Isolation, Identification, and Chromatographic Separation of N-Methyl Derivatives of Glycoluril

1D and 2D NMR spectroscopy for identification of carbamide-containing biologically active compounds

“…The observed difference in the chemical shift of the C=O groups makes it possible to establish the presence of an impurity of compound XVII in substance XII by NMR. Using 13 C, 15 N NMR spectroscopy and quantum chemical calculations, it was shown that the CS in the 13 C spectra of C=O groups of urea does not correlate well with the electron density on the carbon atom [16]. It was found that the shielding of the carbonyl carbon atom in the di(m-chlorobenzhydryl) derivative of XVII in comparison with XII in the Nsubstitution of urea I is due to the presence of «bulky» radicals.…”

“…In study Kurgachev et al [15], we isolated and characterized by chromatography and mass spectrometry analytical methods all possible N-methyl derivatives of glycoluril XXI-XXIV, which can be present as probable products of mebicar X transformation in hydrolysis conditions. In this study we compare the values of chemical shifts in the NMR spectra of N-methylglycoluryl (hereafter, MeGU) X, XXI-XXIV and N,N'-dimethylurea XIX (Table 3).…”

“…4) and heteronuclear correlation methods ( 1 H- 13 C HSQC (Fig. 5) and 1 H- 15 N HSQC (Fig. 6)) were used.…”

“…Doublet of protons of the CH 3 group of N,N'-dimethylurea XIX at 2.53 ppm intersects with a carbon signal in the region of 26.9 ppm. Chemical shifts of nitrogen atoms of 15 N amino groups of ureas I, II, IV, XIX, which have a direct N-H bond, can be determined in the 1 H-15 N HSQC spectrum (Fig. 6).…”

“…Samples of analyzed compounds II-XIII were provided by the Tomsk National Research Medical Center of the Russian Academy of Sciences (Scientific Research Institute of Mental Health). Samples of compounds XIV-XVII and XVIII, XX were synthesized according to the procedures [13,14] and N-methylglycoluryls XXI-XXIV were obtained by the method described Kurgachev et al [15].…”