3,772,414 United States Patent Office Patented Nov. 13, 1973 2 3,772,414 of the desired product and lower reaction efficiency. A PREPARATION OF ESTERS OF method described in U.S. Pat. 2,410,118 is illustrative of PHOSPHORUS ACDS the typical distillation problems encountered. In that Joseph W. Baker and Ignatius Schumacher, St. Louis, method, distillation is difficult due to the high concentra Mo., assignors to Monsanto Company, St. Louis, Mo. No Drawing. Continuation-in-part of abandoned applica tion of Salts of various phosphorus acids in the distilla tion Ser. No. 104,171, Jan. 5, 1971. This application tion still. June 24, 1971, Ser. No. 156,562 U.S. Pat. 2,868,827 describes the use of titanium tetra Int, CI, CO7f 9/08, 9/16 chloride as a catalyst for producing organophosphate es U.S. C. 260-973 16 Claims ters. Disadvantages encountered employing titanium 10 tetrachloride reside in the excessive and lengthy times necessary to obtain desirable yields and the relatively ABSTRACT OF THE DISCLOSUIRE large amounts of the metal halide catalysts required. Fur Esters of phosphorus acids are prepared by an improved ther, when the reaction is conducted in the presence of a process whereby thiol- or hydroxyl-containing organic titanium halide catalyst, recovery of the desired reaction materials and phosphorus halides are reacted at specified 5 product is a problem. At the completion of the reaction, temperatures in the presence of urea catalysts thereby it has been found necessary to wash the reaction mixture providing high yields of substantially pure esters and al with a citrate or tartrate solution which forms a com lowing preparation of selected mono-, di- and tri-esters of plex with the titanium catalyst. The complex is then re phosphorus acids having substantially no side reactant moved by Washing with water followed by drying the contaminations. By means of this improved process, 20 remaining product. mono-, di- and tri-esters of phosphorus acids may be Another disadvantage encountered with the employ Selectively prepared. They are useful as plasticizers and ment of many of the aforedescribed catalysts is the need processing aids, and as intermediates in the preparation of for complicated material-handling procedures for the cata plasticizers, oil additives and functional fluids. lyst. 25 Additionally, preparation of organophosphorus esters by the aforedescribed catalyzed reactions restricts the CROSS-REFERENCES TO RELATED manufacturer in that only one specific type of organo APPLICATIONS phosphorus ester of high purity could be prepared by the This application is a continuation-in-part of copending reaction. Thus, one could not prepare compounds of high application Ser. No. 104,171, filed Jan. 5, 1971 and now 30 purity such as, for example, cresyl diphenyl phosphate, abandoned. bromophenyl diphenyl phosphate, phenyl bis(chloro. phenyl) phosphate, cresyl phenyl phosphorochloridate BACKGROUND OF THE INVENTION and the like. By the aforedescribed procedures, only rela This invention relates to a novel process for the prepa tively impure triorganophosphorusester or esters con ration of organophosphorus acid esters. More particularly, 35 taining the same aryl groups could be prepared, for ex this invention is concerned with a process comprising a ample, triphenyl phosphate, tricresyl phosphate and the urea catalyzed reaction of halides of phosphorus and like. Thus, in the preparation of triorganophosphorus thiol- or hydroxyl-containing organic materials. esters by the aforedescribed procedures, the specific tri Numerous methods have been long known for prepar organophosphorus esters prepared were contaminated by ing organophosphorus esters. One of those methods in 40 side reactants which could only be removed by lengthy volves the reaction of a phosphoryl halide and a mono and difficult washing and distillation procedures. hydric organic compound without the use of a catalyst. Accordingly, the objective of this invention is to pro Such a process is not commercially practical because of vide a novel and improved catalytic process for the prepa the need for lengthy reaction times and the resultant low 45 ration of organophosphorus esters in which the disad yields. Another disadvantage of processes of that type Vantages of the prior art are eliminated and selective is the need for the use of excessive amounts of the mono esterification in high yields with substantially no by hydric organic compound. product contamination is afforded. Another known method comprises the addition of cer tain amines to the aforedescribed reaction mixture to 50 SUMMARY OF THE INVENTION effect higher yields. The cost of the amines and the cost of recovering them for use in the process renders the The objective of this invention is accomplished by a method impractical for commercial operation. novel process, combining a critical combination of cat In still other methods, the reaction is catalyzed, so alyst and reaction temperature, for the preparation of or as to produce greater yields, by adding a metal to the 55 ganophosphorus acid esters wherein high yields of prod reaction mixture, such as copper powder, iron filings, cal uct are formed with substantially no side reactions and cium, aluminum or magnesium; or a halide such as alumi contaminants and whereby stepwise building of the ester num chloride, magnesium chloride or boron trifluoride; is allowed in such a manner that mixed esters are pre or a sulfate such as copper sulfate; or an oxide such as pared in an easy and economical manner. As an exam magnesium oxide or copper oxide. 60 The employment of such catalysts has several attendant ple of the innovative process of this invention, a com inherent disadvantages, among which are low conversion pound such as chlorophenyl cresyl phenyl phosphate may of the starting materials and lengthy reaction times re be conveniently and inexpensively prepared, such prep quired for completion of the reaction. As described in aration being difficult and expensive with known methods U.S. Pats. 2,610,978 and 2,632,018, an insoluble com 65 now available to the art. Further, mixtures of mono-, di plex forms during the reaction when aluminum chloride or tri-chlorophenyl phosphorus esters, mono-, di- or tri is used as a catalyst. cresyl phosphorus esters and mono-, di- or tri-phenyl When alcohols are reacted with a phosphoryl halide, phosphorus esters may all be prepared in the same reac either without a catalyst or in the presence of any of the tion vessel with substantially no contamination by side above-mentioned catalysts, other than magnesium chlo 70 reactants and the products may be separated by distilla ride, undersirable by-products are formed. The by-prod tion without undesirable disproportionation. ucts contribute difficult distillation problems, lower yields The novel process of this invention comprises reaction, 3,772,414 3 4 at specific temperatures, of halides of phosphorus of the cycloalkyl, cycloalkenyl, cycloalkynyl, aryl, heterocyclyl formula or combinations and variations thereof whether sub () X stituted or nonsubstituted. Further, cyclic urea compounds Y--z, are contemplated whether substituted or non-substituted. wherein X represents oxygen or sulfur; Y represents R or There is virtually no limitation on the number of carbon RX wherein R represents alkyl, alkenyl, alkynyl, cyclo or nitrogen atoms in the urea compounds or on the num alkyl, cycloalkenyl, cycloalkynyl, heterocyclyl or aryl; R' ber of carbon or other atoms of substituents attached represents alkyl or aryl; m represents 0 when n is 3, m thereto. Accordingly, the only limitation on the size or represents 1 when n is 2 and m represents 2 when n is 1; arrangement of the urea used is that of practicality and Z represents chloro or bromo; and n represents 1, 2 or 3, O expense. The following list of illustrative compounds is with a compound having the formula therefore to be read in the light of the above teachings. (II) R'XH. Aliphatic and alicyclic ureas: lea wherein R' represents aryl and X represents oxygen or biurea sulfur, in the presence of a urea catalyst. 5 thiourea The reaction sequence involved in the process of this hydroxyurea invention proceeds through the following stages, exempli N-(1-adamantyl) urea fied by the reaction of phenol with phosphoryl chloride: methylurea Sym-dimethylurea unsym-dimethylurea {O)-oh -- POCl3 -) HCl -- {O)-0-poch 20 trimethylurea tetramethylurea {O)-oh -- {O)-0-pool, arm ethylurea 2-nitropropylurea HC O--POCN tetradecylurea + (g(OX-0). 25 syn-dioctadecylurea unsym-trieicoxylurea {O)-OH + (OX),/ poc. - 1,1-dimethyl-3,3-diethylurea N Sym-ditetracontylurea HCl -O--PO Sym-dioctylurea -- (KO) / 30 unsym-diheptadecylurea The phosphorus mono- and di-halidates produced are tetrahexadecylurea valuable intermediates in the preparation of plasticizers, beta-hydroxyethylurea oil additives and functional fluids and are prepared con N-acetyl-N-methylurea veniently by the process of this invention and in high 35 beta-hydroxy-n-propylurea yield with substantially no contamination by side reac dodecylurea tions. dipropionylurea The urea catalysts used in the process of this invention tetramethylbiuret may, in general, be any urea which is characterized by 1,3-dichloroamylurea the presence of a nitrogen atom capable of entering into 40 dodecylbiuret a liquid complex with the phosphorus moiety of Formula tetraethylbiuret I under the conditions of the present process. Essentially thiobiuret all urea compounds capable of forming such complex are tetramethylthiobiuret contemplated as catalysts in this process. octylurea The catalyst concentration which is most effective in Sym-dinonadecylurea the process is a function of many variables, but is gen 45 1,3-dinonadecylurea erally from about 0.001 to 2.0 mole percent based on 1,3-dicyclohexylurea the phosphorus halide. Preferably, from 0.01 to 0.1 mole unsym-dicyclopentylurea percent is considered a practical level. Of course, greater Sym-dicyclopropylbiuret or lesser amounts may be used effectively within the dis diurea of hexamethylene diamine cretion and experience of those skilled in the art. Thus, 50 the following list of urea compounds is intended merely Aromatic ureas: to illustrate the broad scope of the compounds which are tetrabenzylurea useful as catalysts herein since it would be virtually im sym-dibenzylbiuret possible to specifically list each compound intended. unsym-dinaphthylurea Representative ureas which may be used as catalysts in 55 sym-phenanthrylbiuret the process of this invention include the following com tetranitrophenylurea pounds, which are illustrative only and are not to be con 1,3-dichlorophenylurea sidered a limitation since, as defined above, any urea is 1,3-diphenylthiourea suitable providing it is capable of complexing with the sym-dibenzylthiobiuret phosphorus moiety of Formula I, without restriction on 60 tetraphenylurea the number of carbon atoms in the urea molecule itself 1,3-ditolylurea and without restriction as to the substituent groups which sym-ditolylthiourea may be on either the carbon or nitrogen atoms of the S-(p-chlorobenzyl)-thiuronium chloride urea. By way of illustration, ureas of the formulas tetraxylylurea 65 tetranaphthylthiourea R X R R NE X R2 1,3-di-biphenylurea 1,3-diphenanthrylthiourea R N-6–N(,R RX-l-N-C-NC R8 carbanilide O Cyclic and heterocyclic ureas: H. R. 70 cyclobiuret N-C-N-(CH2)-N-C-N ethyleneurea R Yi, cyanuric acid wherein n=2-6 include compounds wherein X is oxygen ethylenethiourea or sulfur and R, R1, Ra and R3 are alkyl, alkenyl, alkynyl, 75 parabanic acid 3,772,414 6 1-methylhydantoin O,S-di-R' phosphorohalidothioates.------O urazole RON 1,3-thienylurea P-Z uracil R s^ 1,3-furfurylurea allantoin S,S-di-R" phosphorohalidodithioates...... O alloxantin (R' s):P-2, barbituric acid OS-di-R phosphorohalidodithioates.------RO S 5,5-dimethylhydantoin N -Z 3a,6a-diphenylglycolurel O 5,5-diphenyl-2-thiohydantoin RS glycouril S,S-di-R' phosphorohalidotrithioates----...------S hexamethylenehydantoin 5-iododeoxyuridine (R's --2, R-phosphonic dihalides.------O orotic acid 5 Ureides: R-4-2, acetylurea R-phosphonothioic dihalides.------S benzoylurea R-4-2, cyanacetylurea 20 Di-R-phosphinic halides------O Aliphatic olefinic ureas: R- -Z vinylurea Di-R-phosphinothioic halides.------S 1,3-diallylurea an R-1–2, 25 RR-phosphonohalidates------O Alicycyclic olefinic ureas: R o--z, 1,3-cyclohexenylurea k Additional illustrative urea compounds which are con R R-phosphonohalidothioates.------S templated as catalysts in the process of this invention are 30 known to those skilled in the art and are set forth at Ro-4-2, pages 649-50 of Synthetic Organic Chemistry by Wagner k and Zook (Willey and Sons, 1953). S-R' R-phosphonohalidothioates------O The types of phosphorus halides utilized and prepared in accordance with this invention may be either starting 35 RS --, materials or intermediates or end products of the proc ess. For instance, a phosphoryl halide may be a starting S-R' R-phosphonohalidodithioates------S material used to prepare a dihalidate phosphorus mono ester such as a R phosphorodihalidate. The R' phosphoro RS ---, dihalidate may be an intermediate in the preparation of, 40 for example, a monohalidate phosphorus diester such as a di-R phosphorohalidate. The di-R' phosphorohalidate In the above formulas, R, R and Z are defined as in may be used as an intermediate in the preparation of a Formula I. phosphorous triester end product. At the same time, As described in Formula I, R represents alkl, e.g., however, the R' phosphorodihalidate and di-R' phospho 45 methyl, ethyl, propyl, butyl, amyl, hexyl, heptyl, octyl, rohalidate may be considered mono and di-ester end decyl, undecyl, dodecyl, pentadecyl, hexadecyl, octadecyl, products of the process of this invention. The phosphorus nonadecyl and eicosyl, whether straight or branched halides utilized are well known to those skilled in the chain in configuration; cycloalkyl, e.g., cyclopropyl, cyclo art. Many are commercially available and all are easily butyl, cyclopenty, ethylcyclopropyl, cyclohexyl, methyl prepared in accordance with the process of this invention. 50 cyclopentyl, methylcyclohexyl, decahydronaphthyl, bicy The compounds are encompassed by the scope of Formula clohexyl (cyclohexylcyclohexyl), tetradecahydrophe I and include, by way of illustration, compounds such as: nanthryl, tricyclohexylmethyl; alkenyl, e.g., ethenyl, propenyl, butenyl, isobutenyl, pentenyl, methylbutenyl, Phosphorylhalides------O trimethylethenyl, hexenyl, heptenyl, octenyl, nonenyl, 55 decenyl, dodecenyl, tridecenyl, hexadecenyl, octadecenyl, 1–z, eiscosenyl; cycloalkenyl, e.g., cyclopropenyl, cyclo Thiophosphoryl halides-...------S pentenyl, cyclohexenyl, cyclohexylcyclohexenyl; alkynyl, r -Zs e.g., ethynyl, propynyl, butynyl, pentynyl, hexynyl, R' phosphorodihalidates------O heptynyl, octynyl, nonynyl, decynyl, tridecynyl, octade 60 cynyl, eicosynyl; cycloalkynyl, e.g., 1-cycloden-4-yl; Ro-4-2, heterocyclic radicals containing oxygen or sulfur in the O-R' phosphorodihalidothioates.------S heteroyclic ring, e.g., thiophenyl, furanyl, tetrahydro furanyl, pyranyl, sulfolanyl; aryl, e.g., phenyl, naphthyl, Ro-4-2, biphenyl, phenanthryl, anthracyl, terphenyl or quater S-R' phosphorodihalidothioates.------O 65 phenyl; and R represents alkyl or aryl, as described above R’s--z, with reference to R. R and R' may be unsubstituted, as described above, or S-R' phosphorodihalidodithioates------S substituted. It is to be understood that the urea catalysts R s-–2, of this invention will catalyze the preparation of organo Di-R' phosphorohalidates------O 70 phosphorus esters in accordance with this invention re gardless of the type or extent of substitution of the radicals (R'o)-1-2, defined as included within R and R' above. Thus the O,O-Di-R' phosphorohalidothioates------S radicals represented by R and R may be substituted with (R'o)-2, any organic moiety except a carboxyl group or a hy 75 droxyl group which may interfere with the reaction. 3,772,414 7 8 The following radicals are illustrative of the substituents thiophenol, thiocresol, thioxylenol, phenylthiophenol, which may occur on the groups represented by R and thionaphthol, allylthiophenol. R’ of the phosphorus halides and R, R, R2 and R of the The compounds of Formulas I and II, described above, urea catalysts: alkyl, cycloalkyl, alkenyl, cycloalkenyl, are generally known in the art and their methods of alkynyl, cycloalkynyl, and aryl as described above. Also, preparation are available in standard texts and reference halo, e.g., chloro, bromo, fluoro, iodo; alkoxy, e.g., me SOCeS. thoxy, propoxy, butoxy, hexoxy, decoxy; cycloalkoxy, e.g., A preferred class of the compounds of Formula I are cyclohexoxy, cyclobutoxy; alkenoxy, e.g., propenoxy; cy those compounds of the formula cloalkenoxy, e.g., cyclopentenoxy; aryloxy, e.g., phenoxy, naphthoxy; cyano; nitro; isonitro; aldehyde; ketone; O e.g., phenoxycarbonyl; alkylcarbonyloxy, e.g., acetyl; alkoxycarbonyloxy, e.g., acetoxy; arylcarbonyloxy, e.g., wherein Y-R or RO wherein R'ssaryl or substituted benzoyl; alkylthio, e.g., ethylthio; arylthio, e.g. phenylthio, aryl and R, Z, m and n are defined in Formula I. Repre naphthylthio, trihaloalkyl, e.g., trifluoromethyl; alkylsul sentative of this preferred class of compounds are phos finyl; e.g., butylsulfinyl; arylsulfinyl, e.g., phenylsulfinyl; 5 phoryl chloride, phosphoryl bromide, phenyl phosphoro alkylsulfonyl, e.g., propylsulfonyl; arylsulfonyl, e.g., dichloridate, p-chlorophenyl phosphorodibromidate, p phenylsulfonyl. nitrophenyl phosphorodichloridate, cresyl phosphorodi Specific phosphorus halides which are encompassed chloridate, o-methoxyphenylphosphorodichloridate, nonyl within the scope of this invention include phosphoryl phenyl phosphorodichloridate, cumylphenyl phosphorodi chloride, phosphoryl bromide, phosphoryl dibromide chlo 20 chloridate, o - biphenyl phosphorodichloridate, naphthyl ride, thiophosphoryl chloride and bromide, phenyl phos phosphorodichloridate, isopropylphenyl phosphorodi phorodichloridate, p-chlorophenyl phosphorodibromidate, chloridate, tert-butylphenyl phosphorodichloridate, di p-nitrophenyl phosphorodichloridate, p-nitrophenyl phos phenyl phosphorochloridate, dicresyl phosphorochloridate, phorodichloridothioate, cresyl phosphorodichloridate, o phenylphosphonic dichloride, p-chlorophenylphosphonic methoxyphenyl phosphorodichloridate, nonylphenyl phos 25 dichloride, methylphosphonic dibromide, chloromethyl phorodichloridate, cumylphenyl phosphorodichloridate, o phosphonic dichloride, diphenylphosphinic chloride, di biphenyl phosphorodichloridate, naphthyl phosphorodi phenylphosphonic bromide, dimethylphosphinic chloride, chloridate, isopropylphenyl phosphorodichloridate, tert diethylphosphinic bromide, phenyl phenylphosphono butylphenyl phosphorodichloridate, isodecyl phosphoro chloridate, p-nitrophenyl phenylphosphonochloridate, dichloridate, S-phenyl phosphorodichloridothioate, Sp 30 cresyl phenylphosphonochloridate. nitrophenyl phosphorodichloridothioate, S-phenyl phos A preferred class of the compounds of Formula II are phorodichloridodithioate, diphenyl phosphorochloridate, those compounds of the formula R'OH. Representative dicresyl phosphorochloridate, dibutyl phosphorodichlori of this preferred class of compounds are phenol, o, m, p date, dihexyl phosphorodichloridate, dioctyl phosphorodi cresol, o-ethylphenol, o, m, p-isopropylphenol, p-tert chloridate, didecyl phosphorodichloridate, O,O-diphenyl 35 butylphenol, p-tert-amylphenol, nonylphenol, Xylenol, o, phosphorochloridothioate, O,O - dimethyl phosphoro m, p-chlorophenol, p-bromophenol, p-iodophenol, di chloridothioate, O,O-diethyl phosphorochloridothioate, chlorophenol, trichlorophenol, pentachlorophenol, p SS - diphenyl phosphorobromidodithioate, S.S. diphenyl cumylphenol, o-cyclohexylphenol, naphthol, methoxy phosphorochloridotrithioate, phenylphosphonic dichloride, phenol, ethoxyphenol, phenoxyphenol, p-nitrophenol, tri p-chlorophenylphosphonic dibromide, methylphosphonic 40 phenol, ethoxyphenol, phenoxyphenol, p-nitrophenol, tri dichloride, chloromethylphosphonic dichloride, phenyl fluoromethylphenol, allylphenol, benzylphenol, vanillin, 4 phosphonothioic dichloride, cresylphosphonothioic di chloro - 3,5 - dimethylphenol, 4 - chloro-1-naphthol, 2 bromide, methylphosphonothioic dichloride, chlorometh chloro - 4 - nitrophenol, cyanophenol, di-tert-butylphenol, ylphosphonothioic dichloride, diphenylphosphinic chlo dimethoxyphenol, methylsalicylate, fluorophenol. Especial ride, diphenylphosphonic bromide, dimethylphosphonic ly preferred of this group are phenol, cresol, cumylphenol, chloride, diethylphosphinic bromide, diphenylphosphino 45 nonylphenol, xylenol, chlorophenol, tert-butylphenol, thioic chloride, dimethylphosphinothioic chloride, eth phenylphenol, isopropylphenol and mixtures thereof. ylmethylphosphinothioic bromide, phenyl phenylphos A specialized class of alcohol which are utilized in ac phonochloridate, p - nitrophenyl phenylphosphonochlo cordance with this invention are alcohols of the formula ridate, cresyl phenylphosphonochloridate, O - phenyl phenylphosphonochloridothioate, O-ethyl phenylphos 50 (III) HO-R' OH phonochloridothioate, S - phenyl phenylphosphonobro midothioate, S-phenyl phenylphosphonochloridodithioate. wherein R' represents isopropylidenediphenylene, e.g., The alcohols and thioalcohols embraced by the scope of Formula II include those compounds wherein R rep qh, resents aryl groups as defined with respect to R and R' 55 of the phosphorus halides, Thus, R' represents phenyl, g alkylphenyl, halophenyl, arylphenyl, cycloalkylphenyl, O CH naphthyl, biphenyl, phenanthryl, anthracyl, terphenyl, quaterphenyl, whether substituted or nonsubstituted. or phenylene, e.g., Specific alcohols of the formula R'XH which will illus 60 trate the types of compounds utilized include phenol, o, m, p-cresol, o-ethylphenol, o, m, p-isopropylphenol, p-tert-butylphenol, p-tert-amylphenol, nonylphenol, 2,4- Xylenol, 2,6-Xylenol, 2,5-xylenol, 2,3-xylenol, o, m, p chlorophenol, p-bromophenol, p-iodophenol, 2,4-dichloro 65 Representative of this special class of alcohols are iso phenol, 2,4,5 - trichlorophenol, pentachlorophenol, o propylidenediphenol, hydroquinone, catechol and resor phenylphenol, p-cumylphenol, o-cyclohexylphenol, alpha cinol. naphthol, beta-naphthol, o-methoxyphenol, p-ethoxy In accordance with the novel process of this invention, phenol, o-phenoxyphenol, p-nitrophenol, n-trifluoro the reaction between the phosphorus halides and alcohols methylphenol, 2-allylphenol, 2-benzylphenol, vanillin, 4 70 to prepare organophosphorus esters proceeds in three chloro - 3,5 - dimethylphenol, 4 - chloro - 1 - naphthol, stages. Use of the catalysts of this invention, in con 2 - chloro - 4 - nitrophenol, 4 - cyanophenol, 2,4-di-tert junction with specific temperatures, produces the desired butylphenol, 2,4-dimethoxyphenol, methylsalicylate, 2 results of this invention. Thus, in the presence of the urea fluorophenol, p-hydroxyacetophenone, 4 - hydroxybenz catalysts of this invention, the first chlorine of, example, aldehyde, thiophenol, p-chlorothiophenol, p-tert-butyl 75 phosphoryl chloride is placed at a temperature of from 3,772,414 9 10 about 85 to about 135° C., preferably 105 C. The sec- urea there is added 94 g. phenol over a one-hour period ond chlorine, i.e., disubstitution, is replaced at a tempera- at a temperature of 100-105 C. The temperature is then ture of from about 130 to about 165 C., preferably 150 raised to 105-110° C. and held for two hours, stripped C. The third chlorine, i.e., trisubstitution, is replaced at and allowed to cool to room temperature. Distillation af a temperature of from about 160 to about 250° C., pref- 5 fords predominantly phenyl phosphorodichloridate. erably 200° C. Of course, the specific temperatures for mono-, di- and trisubstitution will vary with the par- EXAMPLE 3 O ticular phosphorus halide being used, but the comparative To a mixture of 225 g. phosphoryl chloride and 1.6 g. differences in the temperatures for the stages of substitu- 1,3-diphenylurea there is added 94 g. phenol over a pe tion will remain approximately the same. 10 riod of one hour at a temperature of 100-105 C. The Accordingly, the combination of specific temperatures temperature is then raised to 105-110 C. and held for for mono-, di- and tri-substitution of the desired phos- two hours, stripped and cooled. Distillation affords 65.1 phorus halides, together with the catalysts of this inven- percent (105.5 g). phenyl phosphorodichloridate, 8.3 per tion, enable those skilled in the art to prepare mono-, di- cent (13.4 g) diphenyl phosphorodichloridate and 1.5 or tri-organophosphorus esters in selected proportions. 15 percent (2.4 g) triphenylphosphate. Triorganophosphorus esters may be prepared in three EXAMPLE 4. stages, with a different alcohol being added to the phos- es 8. phorus halide reactant at each stage. Similarly, mixtures To a reaction vessel there is added 0.3 mole methyldi of esters may be prepared in one reactor. For example, chlorophosphine sulfide and 0.05 mole ethyleneurea. Over by adding a naphthyl group at the first stage, a chloro- 20 period of one-half hour, a total of 0.3 mple phenol is phenol group at the second stage and a phenyl group added at a pot temperature of 120-125 C. The tem at the third stage, one may use the same phosphorus halide perature is held at 125-130° C. for two hours and then butthe temperaturemerely introduce stages setdifferent forth aboveappropriate to obtain alcohols naphthyl at allowedobtained to predominantly gradually cool Oto -room phenyl temperature. methylphosphono There is chlorophenyl phenyl phosphate as well as naphthyl phos- 25 chloridothioate. phorochloridate and naphthyl chlorophenyl phosphoro- EXAMPLE 5 chloridate. The different compounds may then be recov- To a mixture of 0.3 mole thiophosphoryl chloride and ered separately by methods known in the art. Further, 0.004 mole tetra methylurea there is added 0.3 mole phe selected proportions of various compounds may be pre- nol over a two-hour period at 120° C. The temperature pared in the same reactor. Thus, if one desired a mixture 30 is then raised to 125°C. and held for one hour, The re of naphthyl phosphorodichloridate, naphthyl chlorophen- action mixture is stripped, affording predominantly phen yl phosphorochloridate and naphthyl phenyl phosphoro- yl thiophosphorodichloridate. chloridate in proportions of 2:3:1, such selective propor- EXAMPLE 6 tions of the desired products can be made in accordance with the present invention by adding the intended pro- 35 To a reaction vessel there is added 0.3 mole phenyl portion of each appropriate alcohol in the separate stages. phosphorodichloridate and 0.05 mole difurfurylurea. Over The following examples will serve to illustrate specific a period of approximately one-half hour, 0.3 mole phenol embodiments of the concept of this invention but are not is added at a temperature of 150 C. and the pot tem to be regarded as restrictive of the scope thereof since it perature is then held at 145-150° C. for one hour and the has been found that the catalysts of this invention pro- 40 mixture is allowed to cool to room temperature. Distilla mote the reaction betwen virtually any phosphorus halide tion affords 86 percent diphenyl phosphorochloridate and and any alcohol under the conditions defined herein. 9 percent triphenyl phosphate. EXAMPLE 1. EXAMPLE 7 To a mixture of 225 g. phosphoryle chloride and 1.6 g. 45 T o a mixture of 0.3 mole chloromethylphosphonicdi a1,133etramethyurathere two hour period at a temperature is added of 94100-105 g. phenol C. 9YerThe chloride and 0.05 moie dodecylineathesis ided 0.3 temperature is held at 105 C. for two hours, cooled and playing Erie i"...I stripped of hydrogen chloride and other low boilers. Dis- hour and the mixture is brought to room temperature tillationdichloridate, affords 4.4 93.7 percent percent (7.0 (1949 g) g.)diphenyl phenyl phosphorophosphoro- Distillation affords phenyl chloromethanephosphono chloridate. chloridate and 1.1 percent (2.3 g.) triphenyl phosphate. The following table illustrates further examples of the EXAMPLE 2 reaction of a phosphorus halide and an alcohol or thio To a mixture of 225 g. phosphoryl chloride and 2 g. alcohol in the presence of urea catalyst: TABLE Example Phosphorus halide Alcohol Catalyst 8.------Phosphoryl bromide------o, m, p:Cresol------Urea, 10.9.---- ...- ThiophosphorylPhenyl phosphorodichloridate.------chloride------Xylenol------Ethylphenyi- a------1,3-dioctadecylbiuret.1,3-ditetracontylurea. Il- o-Methoxyphenylphosphorodichlorida Nonylphenol- Tetramethylthiourea. 12. S-phenylphosphorodichloridothioate. o, Imp-Cresol- Tetraundecylurea. 13. - Dicresylphosphorochloridate.------frichlorophenol. - 1,3-dibutylurea. 14.15. SS-diphenylphosphorochloridotrithioate.O, O-dipheny E. -- p-Iodophenol------o-Cyclohexyl phenol. ---- 1,3-ditriacontylthiourea.1,3-diphenylurea. 16-- - Phenylphosphonic dichloride------Thiophenol------Benzylurea. 17. Chloromethylphosphonic dibromide O-Methoxyphenol- - 1,3-dicyclohexylurea. 18- - Phenylphosphonothioic dichloride. Phenoxyphenol-- - Tetrabenzylthiourea. 19.-- - Diphenylphosphinic chloride------. -- Cyanophenol------1,3-biphenylurea. 20------... Diethylphosphinothioic bromide--- -- Methyl Salicylate------1,3-ditolylurea. 22-2. - S-phenylphenylphosphonobromidothioate-Phenyl ESSESS;a a - - - - - Resorcinol----Epyidene diphenol - 1,3-thienylurea.Octylurea. 23. O-phenylphenylphosphorodichloridate.--- -- Eydroquinone - Cyclohexenylurea. 24. S-phenyl phenylphosphorodichloridothioate- Catechol------Tetradecenylurea. 25------p-Chlorophenylphosphorodibromidate.---- p-Cumylphenol. --- Propynylurea. 26. . Cresyl phosphorodichloridate.------ES - 1,3-dinaphthylurea. 27. - E. phosphorodichloridate entachloropheno - Hexylbiuret. 28. - Cumyphenylphosphorodibromidat Phenoxyphenol- 1,3-Dodecylurea. 29-. - Naphthylphosphorodichloridate--- p-Bromophenol-- - 1,3-Hexylbiuret. 30.31------DiphenylErisis:R-2-ethylhexylphosphorochloridate.-- Naphthol.------Fluorophenol- ---- 1,3-cyclopropylurea.1,3-diallylurea. 32. - Phenylphosphonic dichloride------Nitrophenol- - 1,3-cyclobutylurea. 33. - Cumylphosphorodichloridate- -- Nonylphenol- ... 1,3-dipropionylbiuret. 34. - Phenylphosphorodichloridat -- Phenol------1,3-acetylthiourea. lm -m-m-m-m-Hamasammler-in-a-room-m-m-m-mm 3,772,414 11 12 EXAMPLE 35 210 C. for two hours to afford a mixture of cumylphenyl To a mixture of 0.01 mole urea and one mole of cresol diphenyl phosphate and nonylphenyl diphenyl phosphate. there is added one mole of phosphoryl chloride over a EXAMPLE 41 period of one hour at a temperature of 125-140° C. and (1) To a mixture of 225 g. phosphoryl chloride and the reaction mixture is stripped and allowed to cool. urea there is added 109 g. cresol over a period of two Distillation affords cresyl phosphorodichloridate in 99.6% hours at a temperature of 105 C. The temperature is yield. held at 105 C.-110° C. for two hours to afford cresyl EXAMPLE 36 phosphorodichloridate. (1) To a mixture of 225 g. phosphoryl chloride and 10 (2) The temperature of the reaction mixture obtained 1.6 g. tetramethylurea there is added 109 g, cresol over a in (1) is raised to 135° C. and 94 g. phenol is added dur period of two hours at a temperature of 105 C. The tem ing two hours at a temperature of 150 C. and held for perature is held at 105-110° C. for two hours to afford an additional two hours to afford cresyl phenyl phos cresyl phosphorodichloridate. phorochloridate. (2) The temperature of the reaction mixture obtained 5 (3) The temperature of the reaction mixture obtained in (1) is raised to 135 C. and 109 g. cresol is fed into in (2) is raised to 200° C. and an additional 94 g. phenol the reactor over a two hour period. The temperature is is added during two hours. The temperature is held at held at 150° C. for an additional one and one-half hours 200-210° C. for an additional two hours to afford cresyl to afford dicresyl phosphorochloridate. diphenyl phosphate. (3) The temperature of the reaction mixture obtained 20 The embodiments of the invention in which an inclu in (2) is raised to 200° C. and 109 g. cresol is fed into sive property or privilege is claimed are defined as the reactor during two hours. The temperature is main follows: tained at 200-210 C. for two hours to afford tricresyl 1. The process of preparing organophosphorus esters phosphate. according to claim 1 which comprises reacting a phos EXAMPLE 37 25 phorus halide of the formula (1) To a mixture of 225 g. phosphoryl chloride and 2 g. urea there is added 94 g. phenol over a two-hour Yin-P-Z period at a temperature of 105-110° C. The temperature wherein is held for two hours at 110-115° C. to afford phenyl phosphorodichloridate. 30 X represents oxygen or sulfur; (2) The temperature of the reaction mixture of (1) is Y represents R or RX; raised to 135° C. and 109 g. cresol is fed into the reactor R represents alkyl, alkenyl, alkynyl, cycloalkyl, cyclo during two hours. The temperature is held at 150 C. for alkenyl, cycloalkynyl, heterocyclyl or aryl; an additional two hours to afford cresyl phenyl phos R’ represents alkyl or aryl; phorochloridate. 35 m represents 0 when n=3, 1 when n=2 and 2 when n=1; (3) The temperature of the reaction mixture of (2) is in represents 1, 2 or 3; and raised to 200° C. and 122 g. xylenol is added during two Z represents chloro or bromo hours. The temperature is maintained at 220 C. for with a compound of the formula one and one-half hours and the reaction mixture is 40 R'XH vacuum treated and allowed to cool to room temperature. wherein Distillation affords cresyl phenyl xylyl phosphate. R' represents aryl; and EXAMPLE 38 X represents oxygen or sulfur To a mixture of 225 g. phosphoryl chloride and 1.6 g. at a temperature of up to about 250 C. in the presence diphenylurea there is added 94 g. phenol during two hours 45 of a catalytic amount of a urea containing a nitrogen atom at a temperature of 105 C. The temperature is then raised which forms a complex with the phosphorus moiety of to 150° C. while gradually adding an additional 94 g. said phosphorus halide. phenol and the temperature is finally raised to 180° C. 2. The process of claim 1 wherein R' is selected from while gradually adding a final portion of 94.g. phenol. The the group consisting of phenyl, cresyl, cumylphenyl nonyl temperature is held at 200° C. for two hours, stripped 50 phenyl, Xylyl, tert-butylphenyl, phenylyl, isopropylphenyl, and allowed to cool. Distillation affords triphenyl phos chlorophenyl and mixtures thereof. phate. 3. A process for preparing an organophosphorusdi EXAMPLE 39 halidate which comprises reacting a phosphorus halide A mixture of 282 g. phenol, 153.4 g. phosphoryl chlo 55 according to claim 2 with an approximately equimolar ride and 1.6 g. urea is heated to 200 C. over four to six amount of a compound of the formula RXH according hours. The temperature is then maintained at 200 C. to claim 1 at a temperature of about 135° C. in the pres under vacuum for two hours. Distillation affords triphenyl ence of a catalytic amount of a urea containing a nitrogen phosphate. atom which forms a complex with the phosphorus moiety 60 of said phosphorus halide. EXAMPLE 40 4. The process of claim 3 wherein R' is selected from (1) To a mixture of 920 g. phosphoryl chloride and phenyl, cresyl, cumylphenyl nonylphenyl, xylyl, tert urea there is added a mixture of 614 g. cumylphenol and butylphenyl, phenylyl, isopropylphenyl, chlorophenyl and 794 g. nonylphenol during two hours at a temperature of mixtures thereof. 105-110 C. to afford a mixture of cumylphenylphos 65 5. The process of claim 3 wherein said organophos phorodichloridate and nonylphenylphosphorodichloridate. phorus diahalidate is selected from phenyl phosphoro (2) The temperature of the reaction mixture obtained chloridate, phenylyl phosphorochloridate, cresyl phos in (1) is raised to 135 C. and 564 g. phenol is added over phorochloridate, tert - butylphenyl phosphorochloridate, a two hour period. The temperature is held at 150° C. cumylphenyl phosphorochloridate, nonylphenyl phospho for an additional one and one-half hours to afford a mix 70 rochloridate, xylyl phosphorochloridate, isopropylphenyl ture of cumylphenyl phenyl phosphorochloridate and phosphorochloridate, chlorophenyl phosphorochloridate nonylphenyl phenyl phosphorochloridate. and mixtures thereof. - (3) The temperature of the reaction mixture obtained 6. A process for preparing a diorganophosphorus in (2) is raised to 200 C. and 564 g. phenol is added halidate which comprises reacting an organophosphorus over two hours. The temperature is maintained at 200 75 dihalidate with an approximately equimolar amount of a 3,772,414 13 4. compound of the formula R'XH according to claim 1 m represents 0 when n=3, 1 when n=2 and 2 when at a temperature of about 165 C. in the presence of a n=1; catalytic amount of urea containing a nitrogen atom which in represents 1, 2 or 3; and forms a complex with the phosphorus moiety of said Z represents chloro or bromo organophosphorusdihalidate. with an approximately n molar amount of a compound 7. The process of claim 6 wherein said diorganophos of the formula phorushalidate is selected from nonylphenyl phenyl phos R'OH phorochloridate and cumylphenyl phenyl phosphoro wherein chloridate and mixtures thereof. 8. A process for preparing organophosphorus esters O R' represent aryl which comprises reacting, in the presence of a catalytic at a temperature of up to 250° C. in the presence of a amount of a urea containing a nitrogen atom which forms catalytic amount of a urea capable of complexing with a complex with a phosphorus moiety, (1) a phosphorus a phosphorus moiety. halide of claim 1 with an approximately equimolar 12. The process of claim 11 wherein R' is selected amount of a first compound of a formula of RXH of 5 from phenyl, cresyl, cumylphenyl, nonylphenyl, xylyl, claim 1 at a temperature of about 85-135 C. to form an tert-butylphenyl, phenylyl, isopropylphenyl, chlorophenyl organophosphorusdihalidate, (2) adding an approximately and mixtures thereof. equimolar amount of a second compound of formula 13. The process of claim 11 wherein said urea is se R'XH to the reaction product of (1) at a temperature of lected from urea, tetramethylurea, diphenylurea, dodecyl about 130-165 C. to form a diorganophosphorushalidate 20 urea or dipyrrolineurea. and (3) adding an approximately equimolar amount of a third compound of formula R'XH to the reaction prod 14. The process of preparing organophosphorus esters uct of (2) at a temperature of about 160-250° C. according to claim 2 which comprises reacting a phos 9. The process of claim 8 wherein said compound of porus halide of the formula formula R'XH is selected from phenol, cresol, cumyl 25 O phenol, nonylphenol, xylenol, tert-butylphenol, phenyl phenol, isopropylphenol, chlorophenol and mixtures there wherein of. Y represents R or R'O; 10. The process of preparing organophosphorus esters R represents alkyl, alkenyl, alkynyl, cycloalkyl, cyclo according to claim 2 which comprises reacting a phos 30 alkenyl, cycloalkynyl, heterocyclyl or aryl; phorus halide of the formula R" represents aryl; O m represents 0 when n=3, 1 when n=2 and 2 when n=1; Yu-I-7, in represents 1, 2 or 3; and wherein 35 Z represents chloro or bromo Y represents R or R'O; with an approximately in molar amount of a compound R represents alkyl, alkenyl, alkynyl, cycloalkyl, cyclo of the formula alkenyl, cycloalkynyl, heterocyclyl or aryl; HO-R'-OH R’ represents aryl; 40 wherein m represents 0 when n=3, 1 when n=2 and 2 when R' represents isopropylidenediphenylene or phenylene n=1; at a temperature of up to about 250° C. in the presence in represents 1, 2 or 3; and of a catalytic amount of a urea which forms a complex Z represents chloro or bromo 45 with a phosphorus moiety. with an approximately n molar amount of a compound of 15. The process of preparing an organophosphorus the formula ester according to claim 11 which comprises reacting R'XH phosphoryl chloride with an approximately trimolar wherein amount of phenol at a temperature of up to about 250° R' represents aryl; and 50 C. in the presence of a urea catalyst which forms a com X represents oxygen or sulfur plex with a phosphorus moiety. 16. The process of claim 11 wherein said organophos at a temperature of up to about 250 C. in the presence phorus ester is selected from triphenyl phosphate, tricresyl of a catalytic amount of a urea which forms a complex phosphate, cumylphenyl diphenyl phosphate, cresyl di with a phosphorus moiety. 55 phenyl phosphate, nonylphenyl diphenyl phosphate and 11. The process of preparing organophosphorus esters mixtures thereof. according to claim 2 which comprises reacting a phos phorus halide of the formula References Cited O UNITED STATES PATENTS 60 1,785,951 12/1930 Gibson et al. 260- 975 wherein ANTON H. SUTTO, Primary Examiner Y represents R or R'O; - R represents alkyl, alkenyl, alkynyl, cycloalkyl, cyclo U.S. C. X.R. alkenyl, cycloalkynyl, heterocyclyl or aryl; 65 260-345.7, 347.3, 553 R, 553 A, 553 B, 564 A, 564 F, R represents aryl; 930,975 PO-1050" CERTIFICATEUNITED STATES of PATENT CoRRECTION OFFICE Patent No. 3,772, 414 Dated November 13, 1973 Inventor(s) Joseph W. Baker and Ignatius Schumacher It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below: column 5, line 33, "Willey" should read -- Wiley --. - Column 8, line 48, "alcohol" should read -- alcohols --. Column l2, line 24 (Claim l), "according to claim " should be deleted. Column l2, line 66 (Claim 5) "diahalidate" should read -- dihalidate --. Column 13, line 3 (Claim 6), after "of" insert -- a --. Column l4, line l0 (Claim ll), "represent" should read -- represents -- . Column 14, line 12 (Claim ll), delete "capable of complexing" and insert therefor -- which forms a complex -i-. Signed and sealed this 30th day of April 1974.

(SEAL) Atte St : EDWARD M.FLETCHER JR . C. MARSHALL, DA. IN Attesting Officer - Commissioner of Patents

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