FAZALARARASI KATALİZ ŞƏRAİTİNDƏ UNDESİN-1-İN SİNTEZİ

Abstract

The dehydrohalogenation reaction of 1,2-dihalogenundecane was studied in the presence of metal complex catalysts formed by crown ethers with cations of alkali metals under the conditions of interphase catalysis, and a new, efficient and simple method for the synthesis of undecine-1 was presented. The use of crown ethers in this method enables the process to be carried out at a very low temperature and under mild conditions. This, in turn, prevents the purchase of various waste and toxic products. In our study, the regularities of the dehydrohalogenation reaction of 1,2-dihalogenundecann were studied in order to determine the optimal conditions of the process, to investigate the cause of the by-product formation and to increase the yield of the product. The effect of various complexing agents, alkalis, solvents, as well as the concentration of DB18K6 and KOH on the yield of the product was studied. It was determined that increasing the concentration of KOH from 25 mmol to 50 mmol increases the yield of undecine 1, but increasing the concentration at a later stage leads to the isomerization of undecine 1 to unadiene-1,2. Also, as the concentration of DB18K6 increases, the output of undecin-1 increases. This indicates that indeed the dehydrohalogenation process takes place in the organic phase, and the transfer of alkali to the organic phase is a key factor in this process. In the proposed method, conducting the dehydrohalogenation reaction of 1,2-dihalogenundecane under the conditions of interphase catalysis with the presence of metal complex catalysts formed by crown ethers with cations of alkali metals differs from the traditional method known in the literature by several advantages. Cheap, harmless solvents are used in the reaction. The reaction is carried out at low temperature (100-130oC). KOH is used as the base, and crown ethers (DB18K6) are the most stable catalysts. It is possible to regenerate the catalyst. As a result of all this, the yield of the product is high (96-98%).