1，3，5-三氟苯合成方法？ us6127577介绍了相关的合成,简介如下: preparation of 1,3,5-trifluorobenzene a two gallon (7.8 liter) stirred stainless steel pressure reactor (parr instrument co., moline, ill.) was equipped with a 1".times.10" stainless steel distillation column packed with propak extruded metal packing. the top of the column was fitted with a reflux condenser and needle valves for venting gases and removing product. a thermocouple was fitted just above the column packing. the column was wrapped with heating tape and insulation to minimize heat loss. the reactor was charged with 33.4 moles of dry n,n'-dimethylimidazolidinone (dmi) (3800 g), 6.15 moles of 1,3,5-trichlorobenzene (tcb) (1118 g) and 22.2 moles of potassium fluoride (kf) (1286 g). the reactor was then sealed. nitrogen was twice charged (200 psig), then vented to remove air. the reactor was then stirred vigorously (760 r.p.m.) and heated to from about 310.degree. c. to about 315.degree. c. after reaching 310.degree. c., nitrogen was vented from the reactor through the valve at the top of the condenser. after from about 2 to about 2.5 hours heating, the tfb produced was distilled off slowly through the take-off valve at the top of the condenser at a rate of about 100 ml/hr. the tfb was removed over a period of from about 6 to about 7 hours. the reactor was then cooled and the salts were filtered off from the dmi. the salts were washed with methylene chloride to recover all the dmi. alternately, other solvents, such as methyl t-butyl ether (mtbe), could also be used. the filtrate and solvent washes were combined and distilled for recovery of both the wash solvent and dmi. distillation of mtbe was done at atmospheric pressure while dmi was recovered by reduced pressure distillation of about 118.degree. c.@28 mm hg. for high purity, the tfb must be re-distilled.查看更多
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