SYNTHESIS AND PROPERTIES OF THE DIPROPARGYL DIETER DERIVATIVE 2-BROMINE-2- NITRO-PROPANDIOL-1,3 (BRONOPOL)

Sc.D., Professor Makhsumov Abdulhamid Assistant Auesbaev Alisher Doctor of Chemistry, Professor of the Department of Chemical Technology of Oil and Gas Processing, Honored Inventor of the Republic of Uzbekistan, Full Member of the Academy of Healing of Uzbekistan, Academician A.S. Turon, Tashkent Institute of Chemical Technology, Uzbekistan. Master of Tashkent Chemistry Institute of Technology and Department of Chemical Technology of Oil and Gas Processing, Uzbekistan

Introduction. The traditional method of synthesizing bronopol, mainly consists in first adding and then brominating. Non-polar toxic and flammable solvents such as ethyl acetate, carbon tetrachloride or dichloroethane must be used in the bromination reaction. The main salt formation of the nitro alcohol intermediate is not stable in the reaction, which is extremely disadvantageous for industrial production: therefore, it is necessary to improve its synthesis path by first brominating nitromethane with the formation of a stable intermediate bromonitromethane and then adding formaldehyde to the reaction to form bronopol.

12(42), December 2019
The currently intensively developing chemistry of acetylene derivatives of 1,3-propanediol (bronopol), pyrazoles, and urea compounds has attracted the attention of many researchers, both in Uzbekistan and abroad [1][2][3][4][5][6][7][8][9][10]. This is due, on the one hand, with the rich possibilities of various chemical transformations that acetylene esters, 2-bromo, 2-nitro-propanediol-1,3, as well as derivatives of pyrazole, urea groups in the molecules of one organic compound represent, and with on the other hand, with different properties valuable for the practical use of the most organic compounds with the above-linked groups.
2-Bromo-2-nitro-propanediol-1,3 or bronopol has a wide spectrum of antibacterial activity [11][12]. Bronopol is even used as a laboratory preservative for milk and as a biocide. Bronopol -found application in water treatment. At this end of use, large volumes of industrial water can be stored and recycled through large evaporative cooling towers, while smaller cooling towers can be used in hotels and public areas of the anti-water building used in air conditioning systems. Therefore, the selected bronopol biocide is effective for large dilutions with an inexpensive, non-volatile, non-aggressive and preferably non-foaming effect, and is also used in pool cleaning. In addition, bronopol is used as a biocide and preservative in technological fluids, paper mills, personal care products, metalworking fluids, fuel storage tanks oils, as well as in water-based paints, inks and adhesives [13][14][15][16][17].
Therefore, in order to expand the derivatives of bronopol as food products, preservatives, in almost all sectors, primarily in the food industries, cosmetics, chemical, pharmacy, medicine, and agriculture, derivatives of bronopol can be used. They are considered an important component to make food safe, leather, cosmetic, medicinal, pharmaceutical and many other sectors of the economy. Compared to other preservatives, bronopol has its advantages.
From the literature it is known that derivatives of dipropargyl ethers have various types of superbiological activity. For example, acetylene containing esters, nitro-bromine contained in one carbon, 1,3-propanedihydroxy possess growth-promoting, antimicrobial, antiseptic preservatives for dairy products, in the manufacture of cheese, which reduce bad cholesterol and blood sugar, as well as many other activities [25 -30].
In the literature [31][32][33], the synthesis of various N, S acetylene compounds with a terminal triple bond is given. However, information on the synthesis of glycerol diacetylene compounds in the 1,3positions, and in the 2-position containing bromo and nitro groups and their derivatives of the type: we have not found, these little-known compounds essentially represent a new kind of compounds whose properties have not been studied. In this regard, we obtained derivatives of the 1,3-dipropargyl diester of 2-bromo-2-nitro-1,3-propanediol interacting with propargyl bromide in the presence of an organic solvent of 2-bromo-2-nitro-propanediol-1,3 according to the scheme: The obtained derivatives of 2-bromo-2-nitro-dipropargyl diester propanediol-1,3 are highly soluble substances in many organic solvents and sparingly soluble in water.
Based on the foregoing, previously unknown compounds were synthesized containing various hetero atoms − ≡ −, in connection with the fact on their basis various functional five-membered heterocycles with potentially very high pharmacological and biological activity can be obtained.
The synthesis of the derivative 1,2 -pyrazole (IX) was carried out by the interaction of the drug (I) with diazomethane according to the following reaction scheme: 4,4΄bis (pyrazolyl-hydroxymethylene) 2-bromo-2-nitro-1,3-propanediol -(IX) the structure of the obtained compound was confirmed by elemental analysis and IR-spectroscopy.
Physico-chemical parameters are given in table. 5. The aromaticity of the cycle is preserved, but the ability to electrophilic substitution at carbon atoms decreases sharply. At the same time, the presence of undivided pairs in heteroatoms increases the probability of an electrophilic attack on nitrogen, contributing to tautomeric transformations and the formation of quaternary salts.
The mutual influence of the lone electron pairs of heteroatoms and the π-electron sextet of the ring is even more important in determining the inclined ability of these heterocycles, 1,2-pyrazoles exhibit weak acidic properties.
Thus, the reflected achievements and modern level of work in the field of chemistry of derivatives of heterocyclic systems convincingly show and prove that in recent years, methods for the synthesis of heterocyclic esters of 1,2-pyrazole or 1,2-pyrazoline have been actively developed. The rings of 1,2pyrazole (or 1,2-pyrazoline) are extremely stable, and many of its derivatives can be distilled without decomposition and melting. Data of the IR-spectra of compounds (IX) are shown in table 6. 1557-1369 Thus, the introduction of a triple bond led to the appearance of a gamma of a variety of pharmacological, physiological, and biological activities, as well as the ability to inhibit metal corrosion, the formation of complex compounds, the formation of polymers, and much more.

The interaction of compound (IX) with hexamethylene diisocyanate (X).
Diisocyanates are among the compounds having an extremely super-high reactivity. Secondary amines with heterocyclic groups containing N-H bonds have the highest reactivity with respect to the isocyanate [14][15][16].
We were the first to obtain derivatives of the tetraurea of the interaction of hexamethylenediisocyanate with compound (IX) at a temperature of 50-55 ° C according to the scheme: The synthesis was carried out in dimethylformamide at a temperature of the reaction medium of 50-52 ° C for 3.0-3.5 hours. It should be noted that the new environmentally friendly tetraurea derivatives are obtained in the form of a snow-white powdery product (X), with fairly high yields, without waste.
The prepared copper chloride solution is added to a dilute alcohol solution of 20.0 g of 2bromo, 2-nitro-dipropargyl diester-propanediol-1,3. The resulting bright yellow precipitate was filtered off and washed with a weak solution of hydroxylamine hydrochloride, water and sulfuric ether. The precipitate is dried in an oven at 50 ° C [].

Synthesis of mercury-bis-(propargyl ether) -2 -bromo-2-nitro-propanediol -1.3 (IV).
In a three-necked flask equipped with a reflux condenser, a stirrer and a dropping funnel, 10 g of mercury acetic acid, 22 g of potassium iodide, 50 ml of water were placed and heated to complete dissolution, after which 18 ml of 10% sodium hydroxide solution were added.
In a three-necked flask equipped with a reflux condenser, a thermometer, and a stirrer,7.44 g (0.02 mol) of bis -(4.4' -pyrazolyl-hydroxymethylene) -βbromo-β -nitro -α, α΄ -propanediol are placed then 25 ml of triethylamine, 40 ml of DMF are added at a temperature of 40 -47 ° C, while stirring, 1.7 g (0.011 mol) of hexamethylene diisocyanate dissolved in 8 ml of DMF are added dropwise. The reaction mixture is stirred for 3.0 hours at a temperature of the reaction mixture of 49 -53 ° C. After the time, the contents of the flask are transferred to a glass, water is added. The precipitate was washed with TLC. After drying, a slightly colored powder is obtained with a yield (X) of 91.7% (of theoretical Conclusions. The currently intensively developing chemistry of acetylene derivatives of pyrazolyl urea compounds has attracted the attention of many researchers, both in the Republic of Uzbekistan and around the world [14][15][16]. This is connected, on the one hand, with the rich possibilities of various chemical transformations that acetylene, urea, and pyrazole groups provide in the molecules of organic compounds, and, on the other hand, with the properties of the most organic compounds with the above-mentioned groups that are valuable for practical use.
There are many examples where the introduction of a triple bond led to the appearance of a gamma of various pharmacological, physiological and biological activities, as well as the ability to inhibit metal corrosion to form complex compounds, form monomers, polymers, and much more.
The further development of acetylene 1,3-propanediol, and their derivatives, is an extremely urgent task of the 21st century.