Polyhaloaromatics. Part V. Synthesis of poly- and perfluoro-1,3,5,7-tetrahydrobenzo[1,2-c:4,5-c′] difurans
作者:Jacek Porwisiak、Wojciech Dmowski
DOI:10.1016/s0022-1139(00)80312-7
日期:1991.1
Treatment of dichloro- or dibromopyromellitic acids 1 or 2 with a mixture of sulphur tetrafluoride and hydrogen fluoride gave the respective 4,8-dihalo-1,1,3,3,5,5,7,7-octafluoro-1,3,5,7-tetrahydrobenzo[1,2-c:4,5-c′]difurans (3) and (4) in high yields. Dichloro compound 3 easily undergoes halogen-exchange with potassium fluoride to give perfluoro-1,3,5,7-tetrahydrobenzo[1,2-c:4,5-c′]difuran (5). Reduction
用四氟化硫和氟化氢的混合物处理二氯-或二溴均苯四甲酸1或2,分别得到4,8-二卤代-1,1,3,3,5,5,7,7-八氟-1,3, 5,7-四氢苯并[1,2-c:4,5-c']二呋喃(3)和(4)。二氯化合物3易于与氟化钾进行卤素交换,得到全氟-1,3,5,7-四氢苯并[1,2-c:4,5-c']二呋喃(5)。根据反应条件,用氢化铝锂还原二溴化合物4,得到1,1,3,3,5,5,5,7,7-八氟-1,3,5,7-四氢苯并[1,2- c:4,5-c']二呋喃(6)或4-溴-1,1,3,3,5,5,7,7-八氟-1,3,5,7-四氢苯并[1,2-c,4,5-c']二呋喃(7)。