2,859,225 United States Patent 0 ’ CC Patented Nov. 4, 1958 1 2 conversion of lead to tetraethyllead above that obtained in present commercial practice without requiring the use‘ 2,159,225 of metallic sodium, metallic lead, alkyl halogen com6 MANUFACTURE or ORGANOLEAD COMPOUNDS pounds, or lead halides. These and other objects of this invention are accom Sidney M. Blitzer and Tillmon H. Pearson, Baton Rouge, plished by reacting a lead chalko'gen, i. e., lead oxide or La., asignors to Ethyl Corporation, New York, N. Y., sul?de, with a non-lead metalloorganic compound of suf a corporation of Delaware ?cient stability under reaction conditions, where the organo portion is a hydrocarbon radical and wherein the No Drawing. Application March 25 1955 10 Serial No. 496,919 ’ metallo element is directly attached to carbon and may additionally be attached to another metallic element. In 13 Claims. (Cl. 260—437) certain embodiments of this invention it is preferred to employ a catalyst. The so-called metalloid elements are not contemplated as they do not form true metalloorganic This invention relates to a process for the manufacture compounds. Thus, this invention comprises the metatheti of organolead compounds. In particular, this invention is cal reaction between lead chalkogen and a non-lead metal directed to a novel process for the manufacture of tetra loorganic compound. 7 ethyllead from lead oxides and sul?des. In general, the metalloorganic reactants of the present The process employed in present commercial practice invention have the general formula M‘R, or M’MIR," for the manufacture of tetraethyllead has been in use for where M1 and M2 are true metals other than lead, R is a number of years and, in general, is satisfactory. How an organic radical, and in particular a hydrocarbon radi ever, it has certain disadvantages which are overcome by cal, and y is an integer from 1 to 4, inclusive. It is not practicing our invention. It proceeds by reacting a sodium intended that the above formulas limit the reactants in lead alloy, of composition controlled to correspond sub the choice of the groups R, as non-lead metalloorganic stantially to NaPb, with ethyl chloride according to the compounds containing a plurality of hydrocarbon radicals, following equation R, can be successfully employed in this invention. In the preferred embodiment of this process the organic radicals are hydrocarbons and particularly are non-aro With the highest yields obtained thereby, only about matic or aromatic radicals. Among the non-aromatic 22 percent of the lead present in the NaPb alloy is con 30 radicals we can employ alkyl or hydrocarbon substituted‘ verted to tetraethyllead. Under conditions of best opera alkyl radicals. In general, we prefer the lower alkyl radi tion of this process, no one heretofore, as far as we are cals having up to about eight carbon atoms. Among the aware, has been able to increase this yield of tetraethyllead aromatic radicals which can be employed in the above by even a few percent, due to the inherent limitation in reaction are included phenyl and hydrocarbon substituted yield as is apparent from the consideration of the above phenyl radicals having up to 10 carbon atoms are satis equation. It should be noted that in this reaction at least factory. Thus, the compounds MR, and M’Mlk, may 75 percent of the lead originally employed is not alkyl be considered alkylating or arylating agents with respect ated. Thus, in this reaction, large quantities of lead must to the lead in the inorganic lead compound. be recovered and reprocessed to NaPb alloy in order to Depending upon the valence of the non-lead metallo make it economical. A further disadvantage of such a element employed, the process of this invention can be large quantity of unreacted lead is that valuable reaction better understood by referring to the following three space in the reaction vessel is occupied by materials which general equations: are essentially inert for the manufacture of tetraethyllead under present conditions and mode of operation. Other processes for the production of organolead com 45 pounds, and in particular tetraethyllead, have been de vised to consume the lead produced in the above equa~ tion. While such processes are satisfactory from the In the equations above, the symbols have the same standpoint of lead consumption, they suffer an additional meaning as hereinbefore de?ned and Y is a chalkogen, drawback in common with the present commercial proc i. e., oxygen or sulfur. In Equation III, n is 0 or 1. Simi ess in that they require organo halide as the ethylating lar equations apply for other metallic elements. agent. One such process is that described in U. S. Patent Among the preferred non-lead metals to be employed 2,535,190 wherein lead as, for example that produced in in the process of this invention are the alkali metals; i. e., the commercial process, is treated with metallic mag lithium, sodium, and potassium; the alkaline earth metals, nesium and ethyl, chloride in the presence of a catalyst, i. e., beryllium, magnesium, calcium, strontium, and preferably an alkyl ether. Thus, in this process as well barium; the group II—B metals, zinc and cadmium; the as the present commercial process, the tetraethyllead group III-A metals, alluminum, gallium, and indium; and manufacturing operation is restricted by the necessary combinations thereof. In such combination, each metal balance between the metallic sodium required and the is only attached to the other metal and to carbon. A pre organic chlorine in the ethyl chloride. A classical method 60 rferred embodiment is the combination of bi-metal metal for the manufacture of tetraethyllead which likewise re loorganic compounds comprising monovalent and tri quires strict balance between metallic magnesium and valent metallo elements. ' organic halide, and has the additional drawback of requir Illustrative of the alkylating or arylating agents which ing highly hazardous ether is the reaction of the so-called can be employed are methyl sodium, methyl potassium, Grignard reagent, for instance ethyl magnesium chloride 65 methyl lithium, dimethyl magnesium, dimethyl calcium, with lead chloride. dimethyl zinc, dimethyl cadmium, trimethyl aluminum,‘ It is therefore an object of this invention to provide a sodium zinc tetramethyl, magnesium aluminum tetra process for the manufacture of organolead compounds methyl, potassium aluminum tetramethyl, ethyl sodium, which overcomes the above objections to the present com ethyl potassium, ethyl lithium, diethyl magnesium, di mercial process and those processes which have been pro 70 ethyl calcium, diethyl zinc, diethyl cadmium, triethyl posed more recently as an improvement there over. Par aluminum, sodium boro tetraethyl, lithium aluminum ticularly, it is an object of the invention to increase the tetraethyl, potassium aluminum tetraethyl, propyl sodi 2,859,225 , 3 4.. um, propyl potassium, propyl lithium, dipropyl magnesi- ’ tetraethyllead can be produced without the co-presence ‘ ut'n, dipropyl calcium, dipropylv ‘zinc, dipropyl cadmium, of ethyl chloride or diethyl ether in the closed vessel. tripropyl aluminum, sodium gallium tetrapropyl, lithium This greatly facilitates ‘control of the reaction and pre aluminum tetrapropyl, aluminum boro tetraethyl, octyl vents the existence of an otherwise hazardous opera sodium, octylpotassium, octyl lithium, dioctyl magnesi tion. After completion of the reaction, the organolead um, dioctyl calcium, dioctyl zinc, dioctyl cadmium, sodi compound produced is in solution in the carrier liquid um aluminum tetraoctyl, potassium aluminum tetraoctyl, and the other products, namely the non-lead oxide, or phenyl sodium, phenyl potassium, phenyl lithium, di sul?de and metallic lead can be removed by ?ltration phenyl magnesium, titanium tetraethyl, diphenyl zinc, di and the organolead compound removed from the car phenyl cadmium, triphenyl aluminum, lithium aluminum 10 rier by distillation. An alternate and successful method tetraphenyl, tolyl sodium, tolyl potassium, tolyl lithium, of recovery comprises discharging the autoclave contents ditolyl calcium, ditolyl zinc, zirconium tetramethyl, tritol into a vessel containing water and recovering the organo yl aluminum, lithium aluminum tetratolyl, potassium lead by steam distillation therefrom. aluminum tetratolyl, naphthyl sodium, naphthyl potas The operation described above can be varied and it is sium, naphthyl lithium, dinaphthyl magnesium, sodium not intended that this invention be limited to the speci?c aluminum tetranaphthyl, lithium aluminum tett'anaph sequence of addition of the reactants. For example, the thyl, and the like. suspension of the non-lead organo metallic compound In addition to the normal alkyl derivatives indicated can be added to the reactor ?rst and then the ?nely di heretofore, branched chain isomers ‘can be employed. vided lead oxide or sul?de added thereto with agitation. Likewise a mixture of two or more compounds MR, 20 . Other modi?cations will be evident. and M’MIR, can be employed, and if- employed along While the above operations were discussed in connec with a redistribution catalyst there is produced a mix tion with a batch operation, they can be successfully ture of organolead compounds containing a multiplicity adapted to a continuous process. In addition to applying-r» #1 of hydrocarbon radicals. Likewise, when the groups R the above operation to a continuous process, other modi are dissimilar, mixed organolead compounds result. ?cations of a continuous process can be made, such as | Among the preferred lead salts employed in this in ?rst mixing together all the reaction materials and then i vention are galena, litharge, massicotite, and chemically passing them continuously through a suitable reaction prepared. lead oxide and sul?de. zone. 7 1 By the process of this invention, as much as 50 per It has been indicated that the process of the present centof the lead in the foregoing lead salts is directly 30 invention is conducted in the presence of an inert car converted to organolead or in particular, in a commercial rier liquid.