Process for the preparation of pure aryllithium compounds and their use

Abstract

A process is described for preparing aryllithium compounds by reaction of metallic lithium in an ether-containing solvent with an aryl halide, wherein prior to or at the beginning of the reaction a catalyst is added, the catalyst containing a halogen-free, polynuclear aromatic (aryl catalyst) or consisting of such a compound.

1 - 16 . (canceled)  
   
   
       17 . A process for the preparation of aryllithium compounds comprising reacting metallic lithium in a solvent comprising ether with an aryl halide, wherein prior to or at the beginning of the reaction, an aryl catalyst is added, said aryl catalyst comprising a halogen-free, polynuclear aromatic compound, wherein lithium metal is in excess based on the total amount of aryl halide.  
   
   
       18 . A process according to  claim 17 , wherein the aryl catalyst is selected from the group consisting of ortho-condensed aromatics and aromatics bonded to one another by single bond.  
   
   
       19 . A process according to  claim 18 , wherein said aryl catalyst is selected from the group consisting of naphthalene, phenanthrene, anthracene, diphenyl and 4,4′-di-tert. butyldiphenyl.  
   
   
       20 . A process according to  claim 17 , wherein the aryl catalyst is added in a quantity of 0.05 to 2 mol. % based on the total amount of aryl halide.  
   
   
       21 . A process according to  claim 17 , wherein the metallic lithium is in finely-divided form, having a particle size of <0.1 mm, and is dispersed in the solvent.  
   
   
       22 . A process according to  claim 17 , wherein the lithium metal has a sodium content of 0.5 to 5 wt. %.  
   
   
       23 . A process according to  claim 17 , wherein an excess of 1 to 40 mol. % lithium is present based on the total amount of aryl halide.  
   
   
       24 . A process according to  claim 17 , wherein said ether is at least one ether selected from the group consisting of an acyclic ether of formula R—O—R′ where R and R′ independently comprise 1 to 6 carbon atoms and a cyclic ether comprising 4 to 8 carbon atoms.  
   
   
       25 . A process according to  claim 17 , wherein diethyl ether, dipropyl ether, dibutyl ether, tert. butyl methyl ether, tert. amyl methyl ether, tetrahydrofuran, 2-methyltetrahydrofuran or tetrahydropyran, individually or in a mixture, is used as the ether-containing solvent.  
   
   
       26 . A process according to  claim 17 , wherein the ether-containing solvent contains, in addition, anhydrous hydrocarbons in a quantity of 50 wt. % at most, based on the total quantity of solvent.  
   
   
       27 . A process according to  claim 17 , wherein a drying agent is added to the lithium metal suspension prior to the addition of the aryl halide.  
   
   
       28 . A process according to  claim 17 , wherein the temperature of the reaction during the addition stage and post-reaction stage is −20° C. to +100° C.  
   
   
       29 . A process according to  claim 17 , wherein the aryl halide used is a halobenzene and the ether-containing solvent used is dibutyl ether and that phenyllithium is obtained as product.  
   
   
       30 . A process according to  claim 30 , wherein the ether-containing solvent contains another ether in addition to dibutyl ether.  
   
   
       31 . A process according to  claim 17 , wherein that the aryl halide used is a halobenzene and the ether-containing solvent used is dibutyl ether in a mixture with cyclohexane or methylcyclohexane and that phenyllithium is obtained as product.  
   
   
       32 . The method of  claim 17 , wherein a catalytically effective amount of aryl catalyst is added.  
   
   
       33 . The method of  claim 17 , wherein the aryl catalyst is not consumed during the reaction.  
   
   
       34 . A method comprising reacting metallic lithium with an aryl halide in a solvent comprising an ether and an hydrocarbon in the presence of a polynucleus aromatic compound to form the corresponding arylithium compound.  
   
   
       35 . The method of  claim 34 , wherein the polynuclear aromatic compound is halogen free.  
   
   
       36 . The method of  claim 34 , wherein the hydrocarbon is cyclohexane.  
   
   
       37 . The method of  claim 34 , wherein the yield of the aryllithium compound is at least 85.6 percent.  
   
   
       38 . The method of  claim 34 , wherein the solvent comprises at least 65% by weight hydrocarbon.  
   
   
       39 . The method of  claim 34 , wherein the solvent comprises diethyl ether and cyclohexane.  
   
   
       40 . The method of  claim 34 , wherein the aryllithium is phenyllithium or p-tolyl lithium.  
   
   
       41 . The method of  claim 34 , wherein the polynuclear aromatic compound is added prior to or at the beginning of the reaction.  
   
   
       42 . A method comprising reacting metallic lithium with an aryl halide in a solvent that comprises ether in the presence of a polynuclear aromatic compound.  
   
   
       43 . The method of  claim 42 , wherein the polynuclear aromatic compound is added prior to or at the beginning of the reaction.  
   
   
       44 . A process according to  claim 42 , wherein the metallic lithium is in finely-divided form, having a particle size of <0.1 mm, and is dispersed in the solvent.  
   
   
       45 . A process according to  claim 42 , wherein the metallic lithium is in finely-divided form, having a particle size of <0.1 mm, and is dispersed in the solvent.