Open AccessSynthesis of alkyl-<i>gem</i>-dichlorocyclopropanes based on isoamylene fraction
Author(s) -
A. I. Musin,
Yu. G. Borisova,
Г. З. Раскильдина,
Р. Р. Даминев,
R.U. Rabaev,
С. С. Злотский
Publication year - 2021
Publication title -
tonkie himičeskie tehnologii
Language(s) - English
Resource type - Journals
eISSN - 2686-7575
pISSN - 2410-6593
DOI - 10.32362/2410-6593-2020-15-6-9-15
Subject(s) - isoprene , alkyl , chemistry , fraction (chemistry) , mass spectrometry , yield (engineering) , nuclear magnetic resonance spectroscopy , organic chemistry , analytical chemistry (journal) , chromatography , materials science , copolymer , metallurgy , polymer
Objectives . The study aims to analyze the dichlorocarbenation of the isoamylene fraction, which is a mixture of 2-methyl-butene-1 and 2-methyl-butene-2, in order to obtain the corresponding alkyl-gem-dichlorocyclopropanes in quantitative yield, and also to determine their structure. Methods . In order to determine the qualitative and quantitative composition of the reaction masses, the following analysis methods were used: gas-liquid chromatography (using the Crystal 2000 hardware complex), mass spectrometry (using a Chromatec-Crystal 5000M device with NIST 2012 database), and nuclear magnetic resonance (NMR) spectroscopy (using a Bruker AM-500 device at operating frequencies of 500 and 125 MHz). Results . Alkyl-gem-dichlorocyclopropanes were synthesized from an isoamylene fraction in the presence of catamine AB as a catalyst. Alternatively, isomeric alkenyl-gem-dichlorocyclopropanes were obtained on the basis of isoprene, and by reduction, the corresponding alkyl-gemdichlorocyclopropanes were synthesized. The synthesized substances were analyzed by gasliquid chromatography, mass spectrometry, and NMR spectroscopy, as previously mentioned above. Conclusions . The results show that the dichlorocyclopropanation of the isoamylene fraction proceeds quantitatively with the formation of a mixture of 2-methyl-2-ethyl-1,1dichlorocyclopropane and 2,3,3-trimethyl-1,1-dichlorocyclopropane. Using isoprene, countersynthesis through successive dichlorocarbenation and hydrogenation was used to synthesize 2-methyl-2-ethyl-1,1-dichlorocyclopropane, one of the products of dichlorocarbenation of the isoamylene fraction.