Abstract

Background. The search for ways to use logging waste is a distinct scientific direction, due to the large number of their permanent formation. The importance of such studies is associated with the need to reduce the loss of valuable wood raw materials in the form of logging waste. One of the possible ways of using waste from logging industries is the production of wood chips using a mobile complex of machines with its further recycling into a wood-fiber semi-finished product. Wood-fiber semi-finished product is, as it is known nowadays, one of the environmentally friendly types of insulation and finishing materials. A significant limitation in the use of wood fiber in various types of production is low fire and bio-resistance. As a consequence, imparting specific properties to a wood-fiber semi-finished product in the form of fire and bio-resistance is an acute problem of the modern wood processing industry.
 Purpose. Synthesis of 4-azofunctionalized pyrazoles with perfluoroalkyl substituent by cyclocondensation of polyfluorinated beta-diketones to confer special properties to the wood-fiber semi-finished product.
 Materials and methods. The 1H, 13C NMR and 1H-13C HSQC spectra were registered at the Krasnoyarsk Regional Center for Collective Use of the FITC KNC SB RAS on a Bruker Avance III Fourier spectrometer with a frequency of 600 MHz equipped with sensitive helium probes with a diameter of 5 mm and 1.7 mm. TMS is used as an internal standard. Chromato-mass spectra were obtained using ISQ 7610 Single Quadrupole GC-MS and Shimadzu LC/MS-2020 instruments. Methyl alcohol was used as the mobile phase. IR spectra were recorded on the FT-801 (FT-801) SIMEX IR Fourier spectrometer with a spectral range from 450 to 5700 cm-1. UV spectra were recorded on a HELIOS OMEGA spectrophotometer equipped with a tungsten-halogen lamp in quartz cuvettes with a diameter of 1 cm at a concentration of 1·10-4 mol/l for 200-400 nm and a concentration of 1·10-2 mol/l for 400-800 nm in ethanol. Melting temperatures were determined in open capillaries on a PTP device (TU 25-11-1144-76).
 Results. 3 new compounds were synthesized: 3(5)-(thiophene-2-yl)-4-nitroso-5(3)-(trifluoromethyl)-1H-pyrazole, 3(5)-phenyl-4-nitroso-5(3)-(trifluoromethyl)-1H-pyrazole and 3(5)-(naphthalene-2-yl)-4-nitroso-5(3)-(trifluoromethyl)-1H-pyrazole.
 Conclusion. Thus, 3(5)-(thiophene-2-yl)-4-nitroso-5(3)-(trifluoromethyl)-1H-pyrazole, 3(5)-phenyl-4-nitroso-5(3)-(trifluoromethyl)-1H-pyrazole and 3(5)-(naphthalene-2-yl)-4-nitroso-5(3)-(trifluoromethyl)-1H-pyrazole. Complex separable mixtures of substances containing pyrazoline, β-diketone and target nitrosopyrazoles were formed by a single-reactor method. The two-stage method of production proposed by us increases the purity and yield of the target products.

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