United States Patent Office

3,457,305 United States Patent Office Patented July 22, 1969 2 and allows the reaction to be carried out economically 3,457,305 at substantially lower temperatures with shorter reaction PREPARATION OF ORGANOTHOPHOSPHORUS periods than were heretofore possible. Moreover, the use HALDES of halide catalyst is advantageous since corrosion of re Joseph W. Baker, Kirkwood, Leo C. D. Groenweghe, action equipment is substantially reduced when the process Olivette, and Raymond E. Stenseth, St. Louis, Mo., 5 assignors to Monsanto Company, St. Louis, Mo., a is carried out at less severe temperatures. corporation of Delaware In accordance with this invention phosphorus com No Drawing. Filed Dec. 28, 1965, Ser. No. 517,091 pounds selected from the group consisting of compounds int. Cl. C07f 9/42, 9/20, 9/04 represented by the formula U.S. C. 260-543 12 Claims 10

ABSTRACT OF THE DISCLOSURE Process for the preparation of organophosphonothioic dihalides (RP(S)Xal and diorganophosphinothioic 5 wherein R, which can be the same or different, is hydro halides RP(S)X which comprises reacting an organic carbyl of not more than 18 carbon atoms bonded to the sulfide RSJ with a phosphorus trihalide PX) where phosphorous atom through a carbon-phosphorus bond, in R is hydrocarbyl of not more than 18 carbon atoms X is halogen (Cl, Br, F and I) and n is an integer from and X is halogen in the presence of a halide catalyst. 0 to 1, and mixtures thereof are prepared by the process which comprises reacting an organic sulfide of the formu la R2S with a phosphorus trihalide of the formula PX, This invention relates to an improved process for the wherein each R is hydrocarbyl of not more than 18 car preparation of compounds of phosphorous and more par bon atoms and X is as defined above, in the liquid phase ticularly to an improved process for the preparation of in the presence of a halide catalyst selected from the organophosphonothioic dihalides and diorganophosphin group consisting of (a) organic halides of the formula othioic halides. (R')-X wherein R’ is hydrocarbyl of not more than Organophosphonothioic dihalides and diorganophos 18 carbon atoms selected from the group consisting of phinothioic halides have been prepared heretofore by alkyl, alkenyl, alkynyl, cycloalkyl and aralkyl, X is halo the process which comprises reacting an organic sulfide gen (Cl, Br, I and F) and m is an integer from 1 to 3, with a phosphorus trihalide in the liquid phase at a tem 30 (b) inorganic halides of the formula Mexy wherein Me perature from about 100° C. to 350° C. This process, is selected from the group consisting of metal and NH4, which is disclosed and claimed in copending application X is halogen (Cl, Br, I and F) and v is the actual valence Ser. No. 515,725, can be represented by the following of Me and is an integer from 1 to 6 and (c) halogens non-stoichiometric expression 35 selected from the group consisting of Cl2, Br2 and I2. S S Mixtures of the above halide catalysts also can be em ployed in the process of this invention. R2S -- PX8 - RPX -- RPX Representative organic halide catalysts of the formula In accordance with the above represented reaction, the (R')Xm which can be used in this invention include by process results in the concomitant production of organo 40 way of example alkyl halides such as methyl chloride, phosphonothioic dihalides (RP(S)X) and diorganophos methyl iodide, methyl bromide, methyl fluoride, ethyl phinothioic halides (R2P(S)X). When substantially equi chloride, ethyl iodide, ethyl bromide, ethyl fluoride, di molar amounts of reactants are employed, the organo chloroethane, n-propyl chloride, n-propyl bromide, iso phosphonothioic dihalides generally comprise a major propyl iodide, n-butyl bromide, Sec-butyl iodide, tert-butyl amount of the product phosphorus compounds and the bromide, 1,3,3-trichlorobutane, 1,3,3-tribromobutane, diorganophosphinothioic halides a minor amount of 45 pentyl chloride, pentyl bromide, 2,3-dichloropentane, 3,3- the product phosphorus compounds. However, the ratio dibromopentane, hexyl chloride, hexyl bromide, 2,4- of diorganophosphinothioic halide to organophosphono dichlorohexane, 1,3 - dibromohexane, 1,3,4 - trichloro thioic dihalide in the product phosphorus compounds can hexane, heptyl chloride, heptyl bromide, heptyl fluo be increased by using an excess of organic sulfide re ride, 1,3-dichloroheptane, 1,4,4-trichloroheptane, 2,4- actant. In said process at temperatures below about 250 50 dichloromethylheptane, octyl chloride, octyl bromide, C., the yield is often uneconomical unless the reaction octyl iodide, 2,4-dichloromethylhexane, 2,4-dichloro is carried out over a period of several days to several octane, 2,4,4-trichloromethylpentane, 1,3,5-tribromo weeks. Furthermore, even at relatively high temperatures, octane and the straight and branched chain nonyl, e.g. above 275 C., organic sulfides only react very slow decyl, undecyl, dodecyl, tridecyl, tetradecyl, pentadecyl, ly with phosphorus trihalides and the yield over a reason 55 hexadecyl, heptadecyl, and octadecyl chlorides, bromides, able reaction time is low. Severe liquid phase reaction tem fluorides and iodides; alkenyl halides such as vinyl chlo peratures, e.g. above 350° C., are not a solution since the ride, vinyl bromide, allyl chloride, allyl bromide, 3-chloro organophosphonothioic dihalides and diorganophosphin n-butylene-1, 3-chloro-n-pentylene-1, 4-chloro-n-hexyl othioic halides are sensitive to temperature and some de ene-2, 3,4-dichloromethyl -n - pentylene - 1, 3-chloro composition occurs, thus reducing yield. 60 n-heptylene - 1, 1,3,3-trichloro-n-heptylene - 5, 1,3,5- Accordingly, an object of this invention is to provide trichloro - n - octylene - 6, 2,3,3-trichloromethylpen an improved liquid phase process for the preparation of tylene-4, and the various homologues and isomers of organophosphonothioic dihalides and diorganophosphin alkenyl halides having 2 to 18 carbon atoms; alkynyl othioic halides. Other objects will be apparent from a con halides such as propargyl chloride, propargyl bromide, sideration of the following disclosure. propargyl iodide and the various homologues and isomers The above and other objects of this invention are ac of alkynyl halides having 3 to 18 carbon atoms; cyclo complished by carrying out the process which comprises alkyl halides such as chlorocyclopentane, bromocyclo reacting an organic sulfide with a phosphorus trihalide pentane, 2,4-dichlorocyclopentane, chlorocyclohexane, in the presence of a halide catalyst. The use of halide bromocyclohexane, 2.4 - dichlorocyclohexane, 2,4,5- catalyst in accordance with this invention materially trichlorocyclohexane, chlorocycloheptane, 2,5 - dichloro accelerates the reaction rate, results in improved yield cycloheptane, 2,4,5-tribromocycloheptane, and the like, 3,457,305 3 4. and aralkyl halides such as benzyl chloride, benzyl bro but the reaction time is increased substantially at such mide, chlorophenylethane, bromophenylethane, 2,4- lower temperatures. Preferably the reaction is carried dichlorophenylethane, 2, 4, 5 - trichlorophenylethane, out at temperatures above about 150° C. from the stand 2,4,6- tribromophenylethane, di(2,4-dichlorophenyl)- point of optimum conversion in reasonable reaction methane and the like. The preferred organic halide periods. catalysts of the formula (R'}X are those wherein The reaction can be carried out at subatmospheric, R’ is alkyl, alkenyl, alkynyl, cycloalkyl or aralkyl hav atmospheric or superatmospheric pressure, the pressure ing not more than 8 carbon atoms, X is chloride and not being critical. The exact reaction conditions, i.e. time, m is an integer from 1 to 3. temperature and pressure, will depend upon the specific Representative metallic halide catalysts of the formula 0 organic sulfide employed. The reaction also can be carried MeX which can be used in this invention include by out in the presence of an inert organic medium. Suitable way of example the halides of Na, K, Ti, Ba, Al, Sb, As, organic media include, for example, Xylene, mesitylene, Be, Bi, Cd, Ce, Co, Cu, Ga, Au, In, Fe, La, Pb, Mn, Hg, “Decalin,” dichlorobenzene, "Tetralin' and chlorinated Nb, Ni, Os, Re, Se, Ag, Ta, Tl, Sn, Zn, and the like. biphenyls. Specific examples of suitable inorganic halide catalysts 5 The separation of the desired phosphorus compound of the formula Mexy include by way of example and not from the product mixture is readily accomplished by limitation: AlBr3, AlCl3, AIF, Sbbr, SbCl, Sbis, SbCls, conventional means well known in the art, e.g. fractional Sb, Sb, AsBr3, ASCl3, NbCl, NiBr, NiCl2. NiI2, distillation under reduced pressure, selective extraction, OSF6, ReCl3, AsFe, Asia, BeBr2, BeCl2, BeF2, Bel2, fractional distillation using a carrier gas, film distillation, BiBr3, BiCl, BiBr, Bils, CdBr2, ReCls, SeFA, AgBr, 20 elution or any suitable combination of these methods. AgF, Ag, TaCl, CdCl2, Cdf2, CdI2, CeCl3, CoBr2, The phosphorus compounds prepared by the process CoCl2, CoI2, CuBr, CuBr2, CuCl, CuCl2, TaBr3, TICls, of this invention and numerous uses therefor are well SnBr2, SnCl2, ZnBr2, ZnCl2, Cul, GaBr3, GaCl3, Gals, known in the art. These compounds are useful as fire AuBr, AuBr3, AuCl, AuCl3, Aus, InBr3, InCl3, Zn2, retardants and rust inhibitors and as chemical interme NaCl, NaI, NaBr, KCI, NHCl, InIs, FeBr2, FeBrs, 25 diates in the preparation of petroleum additives, agricul FeCl2, FeCls, FeBr, Fe2, LaBr3, LaCls, LaI3, PbBr2, tural chemicals, organophosphorus polymers and other KBr, SnCl4, TiCl, TiBri, Tila, NHAI, PbCl, Pb2, products of commercial interest. For example, valuable MnBrs, MnOlo, Mn, Hgbra, HgBr, HgCl2, HgE2, HgI2. lubricity additives for lubricating oils can be prepared by NbBrs, ReClTaCls, ZnCl2, Kl, BaCl2, NH.Br. reacting the phosphorus compounds prepared by the proc The amount of catalyst employed is not critical. The 30 ess of this invention with phenol at temperatures from exact amount will vary somewhat depending upon the about 80° C. to about 150° C. in the presence of an acid specific catalyst and the specific organic sulfide reactant. acceptor in accordance with the following equations: The catalyst is present in a catalytic amount, generally from about 0.0005 mol to about 0.2 mol per mol of organic sulfide reactant. However, greater or lesser 35 amounts can be employed if desired. Preferably, the cata wherein R and X are as defined above. lyst is present in an amount of at least about 0.005 mol The following examples will illustrate the invention. per mol of organic sulfide reactant. Parts and percent are by weight unless otherwise indi Representative R hydrocarbon radicals for the com cated. pounds of the above formulae prepared by the process 40 EXAMPLES 1 to 6 of this invention include by way of example alkyl (1 to In Examples 1 to 6 the following procedure is em 18 carbon atoms) such as methyl, ethyl, n-propyl, iso ployed. Equimolar amounts of methyl sulfide and phos propyl, n-butyl, sec-butyl, isobutyl, tert-butyl, amyl, phorous trichloride, together with catalyst if one is used, hexyl, heptyl, octyl, nonyl, decyl, dodecyl, tetradecyl, are sealed in a pressure vessel and heated at the tempera hexadecyl, octadecyl and the various homologues and iso 45 tures and for the time intervals given in Table 1. At mers of alkyl having from 1 to 18 carbon atoms; alkenyl the end of the reaction period, the vessels are cooled (2 to 18 carbon atoms) such as vinyl, allyl, n-butenyl-1, and the product mixtures subjected to gas chromato n-butenyl-2, n-pentenyl-2, hexenyl-2, 2,3-dimethylbute graphic analysis. Results and further details are given nyl-2-, n-heptenyl, n-decenyl, n-dodecenyl and the various in Table 1. homologues and isomers of alkenyl having 2 to 18 car 50 bon atoms; alkynyl (3 to 18 carbon atoms) such as pro pargyl and the various homologues and isomers of alkynyl having from 3 to 18 carbon atoms; cycloalkyl and alkyl TABLE 1. substituted cycloalkyl (3 to 18 carbon atoms) such as Reaction colliditions Products cyclopentyl, cyclohexyl, mono- and polymethylcyclo 55 hexyl, mono- and polyethylcyclohexyl, cycloheptyl and Ex. Catalyst Temp. Time CHP(S) Cls (CH3)2P(S) Cl 1------None------250 12 Trace Trace the like, cycloalkenyl and alkyl substituted cycloalkenyl 2------I'------245 8 46.9 10.8 3------12'------260 S 49.4 7.8 (3 to 18 carbon atoms) such as cyclopentenyl, cyclohex 4------CH33---- 260 8 53. 6 8.0 enyl, cycloheptenyl, mono- and polyethylcyclohexenyl 5------None.------275 12 8.3 1.5 and the like; aryl (6 to 18 carbon atoms) such as phenyl, 60 6------CH33--- 275 12 3S. 6 13.0 biphenyl, naphthyi, and the like; aralkyl (7 to 18 carbon 1 Product expressed as weight percent of product mixture. atoms) such as benzyl, phenylethyl, diphenylmethyl and 2 Catalyst present at 0.04 mol permol of methylsulfide. the like, and alkary (7 to 18 carbon atoms) such as 3 Catalyst present at 0.05 molper mol of methylsulfide. tolyl, ethylphenyl, xylyl, butylphenyl, tert-butylphenyl, trimethylphenyl, diethylphenyl, methylpropylethylphenyl 65 and the like. EXAMPLES 7 to 25 In carrying out the process of this invention, the or Equimolar amounts of organic sulfide and the ap ganic sulfide is usually reacted with equimolar amounts propriate phosphorus trihalide are heated at 245 C. for of phosphorus trihalide although an excess of either re 8 hours in the presence of the catalysts listed in Table 2 actant can be employed. The reaction is usually carried 70 below following the procedure of Example 2. At the out at temperatures from about 100° C. to about 350 end of this time the product mixtures are each subjected C. At temperatures above about 350° C. decomposition to gas chromatographic analysis. In all examples, amounts occurs and the yield of phosphonothioic and phosphino of organophosphonothioic dihalide and diorganophos thioic compounds is substantially reduced. Reaction tem phinothioic halide comparable to those of Example 2 are peratures below about 100 C, can be used if desired, 75 obtained. 3,457,305 5 TABLE 2

Organic Sulfide Catalyst Amount Methylsulfide------NaCl------0. Ethyl Sulfide------KBr------0.025 Propyl Sulfide------Zn2------a 0.01. Hexyl Sulfide------HgCl2------0.2 Allyl Sulfide------SnCl4----- a 0.05 Propargylsulfide-- Butyl bromide 0.005 ll-Pentenyl-l sulfide PbCl.----- 0.05 Dodecyl sulfide--- Ethylene d 0.01 Methylsulfide------TiBr:------0.05 a y sm do------KI------0.0005 do------NH4Br------0.001 Phenylsulfide--- - 1,3,5-tri-iodopentane. 0.002 Cyclohexyl sulfide- Propargyl bromide 0.00 l-cyclohexenylsulfi Allyl chloride----- 0.005 Benzylsulfide----- Benzyl chloride--- 0.006 Methylsulfide--- l-bromo-3-iodocyclohexane--- 0.00 Tolyl sulfide------2,2-dichlorodecane------0.007 Methyl Sulfide.------3-chloromethyl-n- 0.0009 pentylene-l. Cyclohepty Sulfide------2-chloro-cycloheptaIle------0.003 1 Mols of catalyst per mol of organic sulfide reactant. The embodiments of the invention in which an exclu 20 4. Process of claim 1 wherein the organic sulfide is sive property or privilege is claimed are defined as aryl sulfide. follows: 5. Process of claim wherein the phosphorous tri 1. Process for the preparation of phosphorus com halide is phosphorus trichloride. pounds selected from the group consisting of compounds 6. Process of claim 3 wherein the alkyl sulfide is of the formula 25 methyl sulfide. 7. Process of claim 4 wherein the aryl sulfide is phenyl sulfide. 8. Process of claim 1 wherein the halide catalyst is an organic halide. wherein R is hydrocarby having not more than 18 carbon 30 9. Process of claim 1 wherein the halide catalyst is atoms selected from the group consisting of alkyl, an inorganic halide catalyst. alkenyl, alkynyl, cycloalkyl, cycloalkynyl, aryl, alkaryl 10. Process of claim 8 wherein the organic halide cata and aralkyl; X is selected from the group consisting of lyst is methyl iodide. Cl, Br, F, and I; and n is an integer from 0 to 1, and 11. Process of claim 1 wherein the organic sulfide is mixtures thereof which comprises reacting in the liquid 35 methyl sulfide, the phosphorus trihalide is phosphorus phase an organic sulfide of the formula R2S with a trichloride and the halide catalyst is methyl iodide. phosphorus trihalide of the formula PX at a tempera 12. Process of claim wherein the organic sulfide is ture from about 100° C. to about 350° C., wherein R methyl sulfide, the phosphorus trihalide is phosphorus and X are as defined above, in the presence of a halide trichloride and the halide catalyst is I. catalyst selected from the group consisting of (a) or 40 ganic halides of the formula (R') X, wherein R is hy References Cited drocarbyl of not more than 18 carbon atoms selected UNITED STATES PATENTS from the group consisting of alkyl, alkenyl, alkynyl, cycloalkyl and aralkyl X is halogen and m is an integer 2,662,917 12/1953 Jensen. from 1 to 3, (b) inorganic halides of the formula Mexy 45 2,685,603 8/1954 Walsh. wherein Me is selected from the group consisting of Na, 2,882,304 4/1959 Weber. K,Ti, Ba,Al,Sb,As,Be, Bi, Cd, Ce, Co, Cu, Ga, Au, In, Fe, La, Pb, Mn, Hg, Nb, Ni, Os, Re, Se, Ag, Ta, Tl, Sn, BERNARD HELFIN, Primary Examiner Zn and NH4, X is halogen and v is the actual valence J. E. EVANS, Assistant Examiner of Me and is an integer from 1 to 6 and (c) halogens 50 selected from the group consisting of I2, Br2 and Cl2. 2. Process of claim 1 wherein the temperature is U.S. C.X.R. above about 150 C. 46-6; 260-961,973 3. Process of claim 1 wherein the organic sulfide is an alkyl sulfide. 55