由三氟异丙烯基溴化镁制备羧酸  

Preparation of Carboxylic Acid from 3,3,3-Trifluoropropenylmagnesium Bromide

作　　者：万洪[1] 谷玉杰[1] 曾纪珺[1] 徐强[1] 吕剑[1] 

机构地区：[1]西安近代化学研究所,西安710065

出　　处：《应用化学》2012年第2期129-134,共6页Chinese Journal of Applied Chemistry

摘　　要：以三氟丙烯和溴为原料加成制得1,2-二溴三氟丙烷,脱溴化氢得到2-溴三氟丙烯,再在一定条件下合成2-溴三氟丙烯的格氏试剂(三氟异丙烯基溴化镁),与CO2反应最终生成1-溴-2-三氟甲基丙酸。用碳酸钠溶液萃取的方法得到0.8 g产品,纯度为99.6%,收率为3.6%。对产物进行了MS、IR、1H NMR和13C NMR等表征,并分析了主要副产物1,2-二氟丙二烯和2,3-二三氟甲基-1,3-丁二烯及其与未反应的2-溴三氟丙烯间的[2+2]或[2+4]环加成反应产物。确定以2-溴三氟丙烯为原料经格氏反应制羧酸较好的反应条件为:以THF为溶剂,1,2-二溴乙烷作引发剂,制备格氏试剂温度为30℃,CO2与格氏试剂反应温度为0℃。Propinic acid containing trifluoromethyl group was synthesized from 2-bromo-3, 3, 3- trifluoropropene, which was obtained via two steps ： addition of 3,3,3-trifluoropropene and bromine followed by an elimination reaction. Then the reaction of magnesium, 2-bromotrifluoropropene, different initiators and carbon dioxide in tetrahydrofuran produced 1-bromo-2-trifluoromethylpropionic, 0. 8 g of the product was obtained by extrated with 10% sodium carbonate solution. The purity of the product was 99.6% and the yield was 3.6%. Its structure was characterized by MS, IR, ^1H NMR and 13C NMR. The main by-products were 1,1-difluoropropadiene, 2,3-bis （trifluoromethyl） -1,3-butadiene and their [ 2 ＋ 2 ] and [ 2 ＋ 4 ] cycloaddition products. The suitable synthesis conditions of the reactions were determined as follows： THF was used as reaction solvent, dibromoethane as the initiator, reaction temperature for preparing the Grignard reagent was 30 ℃, the Grignard reaction temperature was 0 ℃.

关 键 词：溴三氟丙烯 四氢呋喃 格氏试剂 羧酸 环加成 

分 类 号：O622.5[理学—有机化学]