PROCESS FOR PRODUCING 2-FLUORINE-1-CYCLOPROPANE CARBOXYLIC ACID DERIVATIVES BY REDUCTIVE DEHALOGENATION

• Main Authors: MULLER, NIKOLAUS, WOLTERS, ERICH, LUI, NORBERT
• Format: Patent
• Language: English; Korean
• Published: 15.03.2000
• Edition: 7
• Subjects: ACYCLIC OR CARBOCYCLIC COMPOUNDS; CHEMISTRY; METALLURGY; ORGANIC CHEMISTRY

PURPOSE: A process for preparing cyclopropane carboxylic acid derivatives is provide to improve the yield, selectivity and proportion of cis-isomers of the product and to reduce the reaction time and the amount of metals and bases required for the reaction. CONSTITUTION: Cyclopropane carboxylic acid derivatives of the formula 1 where R is OR1 or NR2R3, where R1, R2 and R3 are independent each other and represent straight or branched alkyl group of C1-C4, and X is chlorine, bromine or iodine, are prepared by reacting a halogen cyclopropane carboxylic acid derivative of the formula 2 with a metal in the presence of a base in protic solvent with or without the addition of hydrogen. The metal is one or more metals of the group 2 and/or 8 in the periodic table, for example zinc, iron, cobalt and/or nickel, and may exist with a diluent or as active state such as Raney-form. The suitable base is an organic base, especially amines of the formula 3 such as 1,2-ethylenediamine, diethylenetriamine, triethylenetetraamine, tetramethylethylenediamine and mixtures thereof. The suitable protic solvent is alcohols and mixtures of alcohols and other solvents (for example, ethers and/or aromatic or aliphatic hydrocarbon). The process is performed at 0-120°C, at hydrogen pressure of 1.5-200 bar, and by using 110-250 mol% of the metal based on the amount of the compound of the formula 2. 염기가 반응 중에 첨가되는 이로운 방식으로 염기의 존재하에서, 수소를 첨가하거나 첨가하지 않고, 금속과 할로게노시클로프로판카르복실산 유도체를 반응시킴으로써 시클로프로판카르복실산 유도체가 제조된다. 본 발명에 따른 방법에 의해, 고수율 및 고선택도, 및 반응 생성물 중의 시스 이성질체의 고분율이 달성될 수 있다.