We then applied the synthesized Lawessons reagent to the thionization of glycosylurea derivatives. The proposed method of thionization was based on the interaction of N-methyl-N1-(β-D-glycopyranosyl)-urea (2 - 4) with the Lawessons (1) reagent at a 1:1 ratio of reagents in pyridine, where is formed N-methyl-N¹-(β-D-glycopyranosyl)-thioureas (8 - 10) (Figure 2) [10]. This reaction proceeds quickly, so we could not fix the intermediate formation of the corresponding

products. This is most likely due to the decomposition of the Lawessons (1) reagent into dithiometaphosphonate (1a), which has a resonant structure. The interaction of dithiometaphosphonate with glycosylmethyl urea (2-4) leads to the formation of intermediate cyclic thioketals (5 - 7), with the subsequent decomposition, which produces the final products (8 - 10).

The advantage of this method is the simplicity, acceleration of the process, and elimination from the use of high-pressure technological processes and expensive platinum dioxide, poisonous sodium azide, and bromine reagents. Compounds synthesized by the new method are crystalline substances possessing chemical stability. They can be stored without decomposition at room temperature, stable under thin-layer chromatography (TLC) conditions. The individuality and structure of the target products were confirmed by the methods of nuclear magnetic resonance ¹³С (NMR), ¹Н NMR, infrared (IR)-spectroscopy, also elemental analysis. In the ¹³C NMR and ¹H NMR spectra of as-synthesized compounds, we observed nuclei signals belonging to all presenting compounds (Table 1).

In the IR spectra, in particular of N-methyl-N1-(β-D-glucopyranosyl)-thiourea, a broadband was observed in the region of 3000 - 3550 cm⁻¹, which is characteristic of the stretching vibrations of the OH- and NH- groups. Absorption bands in the regions of 1024 and 1108 cm⁻¹ are related to the stretching vibrations of the carbohydrate ring. The presence of signals at 926 cm⁻¹ is indicating β-position of the pyranotic ring. Oscillations in the region of 1256 - 1441 cm⁻¹ can be attributed to the valence vibrations of the group (C=S). Peaks in the region of 2836 cm⁻¹ are attributing to CH₃ group vibrations.

Important structural information was obtained by the 1H NMR spectra. According to the proton magnetic resonance (PMR) spectrum, the structures of the products obtained are compounds formed from the glycosylamine bond with the β-arrangement of glucosyl methylthiourea. The low-field part of the PMR spectrum for the N-methyl-N¹-(β-D-glucopyranosyl)-thiourea contains signals that appearing as a multiplet centered at 3.6 ppm - 3.8 ppm, respectively, belonging to the fifth axial and the fifth equatorial hydrogen atom of the carbon-water ring. The equatorial hydrogen atom at C-2 appears as a doublet with a chemical shift at 3.8 ppm. A signal in the form of a broadened singlet, belonging to the protons of the methyl group CH₃, is observed in the region of 2.7 ppm. The signal in the region of 4.6 ppm - 4.85 ppm refers to carbohydrate rings.

¹³C NMR spectra of N-methyl-N¹-(β-D-glucopyranosyl) thiourea, the anomeric carbon atoms were found in the range of δ 60.69 - 81.09 ppm, which also testifies favor for the β-configuration of the glyosidic bond. Signals in the region of 60.69 ppm and δ 69.42 suggest that the glucoside residue in the compounds under discussion is in the pyranose form. Signals in the region of δ 26.28 ppm belonging to the methyl group, C=S signals were observed in the field of ≈160.13 ppm. The set of spectral characteristics of the synthesized compounds do not doubt that all the substances obtained are individual compounds.

In a flask equipped with a reflux condenser and a calcium chloride tube, 3.661 g (0.114 mol) of sulfur and 1.4 g (0.045 mol) of red phosphorus placed and boiled. The reaction mass was then cooled, 12 ml (0.11 mol) of anisole was added and boiled. After cooling up to the room temperature, the precipitated crystals filtered and washed with absolute ether and benzene, and then recrystallized from absolute toluene. Product yield: 4.36 g, (47.8%), T_melt = 228˚C - 229˚C. IR spectrum (KBr, v, cm⁻¹): 689 (P = S), 615 (P = C), 1022, 1095, 1180 (R-O-CH3), 1267, 1294, 1308, 1458, 1493, 1592 (arom.). C₁₄H₁₄O₂P₂S₄ 404.475 Calculated %: C-41.57; H-3.49; P-15.32; S-31.71. Found %: C-41.95; H-3.78; R-15.1; S-32.0.

Lawessons reagent was used by us for thionization of carbamide derivatives of sugars to obtain thiocarbamide derivatives, 4-(N-β-D-glycopyranosyl)-thiosemicarbazide [11], previously synthesized by us, N-(β-D-glycopyranosyl) phenylsemicarbazide, 2,3,4,6-tetra-O-acetyl-(β-D-glycopyranosyl)-carbamoyl diethylenediamine, 1-[(N-glycopyranosyl) carbamoyl]-3,5-dimethylpyrazole [10] [12] [13] [14] as shown in Figure 3.

The reaction proceeds smoothly with the interaction of carbamide derivatives of sugars with Lawesson reagent in pyridine, for 20 minutes and leads to the formation of the corresponding 4-(N-β-D-glycopyranosyl)-thiosemicarbazide, N-(β-D-glycopyranosyl) phenylthiosemicarbazides, 1-[(N-β-glycopyranosyl) thiocarbamoyl]-3,5-dimethylpyrazoles, 2,3,4,6-tetra-O-acetyl-(β-D-glycopyranosyl)-thiocarbamoyl diethylenediamine diamine (Figure 4). The course of reactions and compositions of obtained compounds was controlled and carried out using the methods of thin-layer and paper chromatography in the systems: chloroform-ethanol-methyl ethyl ketone (1:2:1).

Compounds synthesized by the method are the crystalline substances possessing chemical stability. They can be stored without decomposition at room temperature, stable under TLC.

Individuality and structures of the target products confirmed by physicochemical methods of ¹³С and Н¹ NMR, IR spectroscopy analyses. Results were presented in Tables 1-4, characteristic maximums of sugar thiocarbamides in the IR spectrum absorption bands, and chemical shifts for ¹³C NMR of sugar thiocarbamides in Figure 5, Figure 6.