Study On Synthesis Of Cyclopropyl Formic Acid And Its Derivatives

Cyclopropyl formic acid is an important chemical intermediate.The advantages and disadvantages of the different synthesis routes of cyclopropyl formic acid are describe.The synthesis route of cyclopropyl formic acid was designed,which was divided into three steps.In the first step,triphenylphosphine is used as a catalyst,the reaction of 1,4-butyrolactone with isopropanol and SOCl₂ proceeds through ring-opening-esterification to form iso-propylchlorobutyrate.The yield of iso-propylchl-orobutyrate was 92.3%and the purity of GC was 97.4%.In the second step,under the solid-liquid two-phase phase transfer catalysis,iso-propylchlorobutyrate and Na OH combine to form isopropyl cyclopropyl formate.The yield of isopropyl cyclopropyl formate was 88.1%and the purity of GC was 96%.In the third step,cyclopropan-ecarboxylic acid was formed by hydrolysis and acidification of isopropyl cyclopropyl formate under alkaline conditions.The yield of cyclopropanecarboxylic acid was 92.4%and the purity of GC was 95.6%.After the second step of the reaction,the solvent CH₂Cl₂ was directly vaporized.Then the sodium hydroxide solution was added for the third step,the total yield of the two steps was 89.8%,and the total yield was increased by 8.4%.The synthesis process of third steps is optimized.After isopropyl cyclopropyl formate is hydrolyzed,isopropanol is distilled off and hen acidified.acidified It can prevent the esterification of isopropanol and cyclopropanecarboxylic acid to form isopropyl cyclopropyl formate.And in the literature,the ethyl acetate of the extractant was changed to dichloromethane.The advantage is that the esterification reaction and transesterification reaction were removed during the post-treatment,and the production of the by-products of ethyl cyclopropyl formate and isopropyl acetate.After optimization,not only the side reactions are reduced but also the reaction yield is improved.The total yield of cyclopropyl formic acid was 82.8%.The cyclopropyl formic acid derivative was synthesized using cyclopropyl formic acid as a raw material.Cyclopropyl formic acid derivatives include cyclopropylformyl chloride?cyclopropyl formic anhydride?cyclopropylformic acid amine?and cyclopropylamine.Cyclopropyl formic acid reacts with PCl₃ to produce cyclopropy-lformyl chloride,with a yield of 93.2%.Under the action of triethylamine,cyclopropyl formic acid reacts with cyclopropyl methyl chloride to produce cyclopropylmethan-hydride,with a yield of 90.3%.At high temperature,cyclopropyl formic acid and urea produce ammonium salt,and the ammonium salt is removed from a part of water to produce cyclopropyl formamide,and the yield is 87%.Cyclic propyl formamide was used for hoffman degradation to get cyclopropanamine,with a yield of 81%.In the synthesis of cyclopropyl formic acid and its derivatives,the intermediates and target products were characterized and analyzed by ¹H NMR?IR and MS.The qualitative analysis was performed by gas chromatography.