United States Patent (19) 11) 4,133,830 Uhing et al. 45) Jan. 9, 1979 54 PROCESS FOR PREPARING ALKYLOR ARYL THOPHOSPHORUS HALDES AND MEXED SOMERS THEREOF 75 Inventors: Eugene H. Uhing, Pleasantville; Francis A. Via, Yorktown Heights, both of N.Y. 73) Assignee: Stauffer Chemical Company, wherein R is a C1 to Coalkyl radical, cycloalkyl of 5-6 Westport, Conn. carbon atoms in the ring and the C1-C4 alkyl substituted derivative thereof, an aralkyl radical of up to two fused (21) Appl. No.: 765,705 rings, the alkyl portion having from 1 to 20 carbon atoms, an aryl radical of up to three fused rings and the 22 Filed: Feb. 4, 1977 C1-C4 alkyl derivatives thereof, and biphenyl and the 51 Int. Cl? .......................... C07H9/34; C07H9/42 C1-C4 alkyl derivatives thereof, X is a halogen of chlo (52) rine or bromine, and Z is either R or X, by the reaction 58) Field of Search ..................................... 260/543 P of a phosphorus halide source, a hydrocarbon source selected from the group consisting of RH, RX and (56) References Cited RSaR, whereina is 1 or 2 and a sulfur source under U.S. PATENT DOCUMENTS autogenous pressure in an autoclave at a temperature 3,429,916 2/1969 Baker et al. ...................... 260/543 P ranging from about 175 C. to about 450° C. by recy 3,726,918 4/1973 Toy et al. ......................... 260/543 P cling to successive runs a by-product of the reaction 3,790,629 2/1974 Uhing et al. ... 260/543 P remaining after separation of the RPCS)XZ product 3,803,226 4/1974 Uhing et al. ... 260/543 P fraction selected from the group consisting of: 3,864,394 2/1975 Ura et al. ... 260/543 P (a) a by-product fraction having a boiling point 3,879,500 4/1975 Uhing et al. ......................... 260/981 lower than the product fraction; 3,897,491 7/1975 Toy et al....... ... 260/543 P (b) a by-product fraction having a boiling point 3,962,323 6/1976 Toy et al. ......................... 260/543 P higher than the product fraction; 3,968,156 7/1976 Uhing et al. ..................... 260/543 P (c) a by-product fraction having a boiling point 3,988,368 10/1976 Ura et al. .......................... 260/543 P 4,000,190 12/1976 Uhing et al. ..................... 260/543 P higher than the product RPOS)XZ wherein Z is R 4,034,024 7/1977 Toy et al. ......................... 260/543 P fraction; (d) XZP(S)RP(S)XZ Primary Examiner-Norman Morgenstern (e) liquid residue; Attorney, Agent, or Firm-Paul J. Juettner (f) solid residue; (g) mixtures thereof; and 57 ABSTRACT (h) mixtures of the preceding with R2P(S)X wherein Improved yields and a lower accumulation of by-pro R and X are as defined hereinbefore. duct is obtained in the method for preparing compounds of the formula: 15 Claims, No Drawings 4,133,830 1. 2 ered substantially and a large quantity of by-product PROCESS FOR PREPARNG ALKYL OR ARYL residue including solid residues was obtained. THOPHOSPHORUS HALDES AND MIXED A portion of the problem can be overcome by recy SOMERS THEREOF cling the by-product R2P(S)X as taught in U.S. Pat. No. 3,790,629. However, this requires a further distillation BACKGROUND OF THE INVENTION step beyond product separation. The problem of solid Field of the Invention and liquid residues as well as low yields would not be The present invention relates to new and improved OVerCOe. processes for the preparation of alkyl or aryl phos Similarly, in the other named reactions, yields as well phonothioic dihalides, and phosphinothioic mono 10 as by-products accumulation can be a problem. halides. It has now been found that yields in these reactions The Prior Art can be easily increased without extensive processing Alkyl phosphonothioic dihalides have been prepared changes. In most instances, by-product accumulation is in the prior art by reacting alkyl halides with phospho reduced or in some cases essentially ceases. rous trihalides in the presence of aluminum chloride, 15 followed by sulfurization of the reaction product. The THE INVENTION alkyl halide/phosphorus trihalide reaction proceeds at In accordance with the present invention, it has now room temperature according to the formula set forth in been found that the yield of product can be increased Heuben-Weyl, Methoden der Organis Chenchemie at and the cumulative yield of by-product can be de Volume 12, Part 1, (1956) at page 396: 20 creased in the autoclave process for preparing com pounds of the formula: XR-C + PCl3 + AlCl3 -> XR - PC4AlCl3 I. S The Heuben-Weyl reference also notes that the reaction has been attempted in the absence of the aluminum 25 /x chloride catalyst with little success. The reaction has RP the disadvantage that one mole of aluminum chloride is N lost for each mole of product prepared. Z. More recently, the prior art has taught that alkyl or wherein R is a C1 to Coalkyl radical, cycloalkyl of 5-6 aryl thiophosphorus halides can be prepared by an auto 30 carbon atoms in the ring and the C1-C4 alkyl substituted clave process at 200° C. to 450° C. under at least autoge derivative thereof, an aralkyl radical of up to two fused nous pressure. Various reactants can be used as outlined rings. The alkyl portion having from 1 to 20 carbon in the following reaction sequences: atoms, an aryl radical of up to three fused rings and the RH + P(S) X-RP (S) X2 + HCl (U.S. Pat. 3,790,629) 3RX + 3ZP (S) X2 + 2P-3RP (S) XZ + 2PX (U.S. Pat. 3,726,918) RSaR + PX + (Sulfur Source)2- + P-RP (S) X2 a = 1, U.S. Ser. No. 551,805 a = 2, U.S. Ser. No. 548,650 Filed: 2/20/75, Toy Uhing . Filed: 2/10/75, Toy and Uhing RX + P(S) X3 + S-RP (S) X2 + SX2 (U.S. Pat. 3,726,918) The thiophosphoryl halide used in these reactions can C1-C4 alkyl derivatives thereof, and biphenyl and the be prepared in situ by the reaction of phosphorus tri C1-C4 alkyl derivatives thereof, X is a halogen of chlo chloride and sulfur from a source of available sulfur. rine or bromine, and Z is either R or X, by the reaction The disclosures of the above noted patents and applica 45 of a phosphorus halide source, a hydrocarbon source tions are incorporated herewith by reference. selected from the group consisting of RH., RX, and Each of these reactions is plagued by low yields, and RSaR wherein a is 1 or 2 and a sulfur source under by-product formation. For instance, the RH/P(S)X3 autogenous pressure in an autoclave at a temperature reaction disclosed in U.S. Pat. No. 3,790,629 can be ranging from about 175' C. to about 450° C. by recy operated successfully on a laboratory scale but the labo 50 cling in successive runs a byproduct of the reaction ratory process cannot be economically scaled up to remaining after separation of the RP(S)XZ product plant scale. In the laboratory, the reaction was con fraction selected from the group consisting of: ducted with large excesses (150%) of hydrocarbon (See (a) a by-product fraction having a boiling point Example 1 of U.S. Pat. No. 3,790,629). A yield of lower than the product fraction; RP(S)X of 70% was obtained. It is indicated that fur 55 (b) a by-product fraction having a boiling point ther increases could be obtained by recycling by-pro higher than the production fraction; duct R2P(S)X. Since the price of the hydrocarbon has (c) a by-product fraction having a boiling point risen significantly and since government regulations higher than the product RP(S)XZ wherein Z is R may not allow venting the excess hydrocarbon into the fraction; air, any manufacturing operation must include a reclai (d) XZP(S)RP(S)XZ; mation or disposal stage for the hydrocarbon. Reclai (e) liquid residue; mation of the hydrocarbon would require the removal (f) solid residue; of entrained HX by-product from the hydrocarbon (g) mixtures thereof; and waste stream. Disposal would involve burning a reac (h) mixtures of any of the preceding with R2P(S)X tant whose price is significant to the economic viability 65 wherein R and X are as defined hereinbefore. of the process. It has suprisingly been found that recycling some and An attempt to reduce the quantity of hydrocarbon preferably all of the by-products of the reaction includ used in the reaction was unsuccessful. Yields were low ing solid residues will result in increased yields. In con 4,133,830 3 4. nection with the reaction between a hydrocarbon and As used in the formulae herein, X is halogen of chlo P(S)Cl3, yields as high as 92% have been obtained using rine or bromine, preferably chlorine. For most interme substantially stoichiometric quantities of hydrocarbon. diate type reactions, chlorine is preferred. Bromine, It has also been surprisingly found in connection with though more expensive than chlorine, can be used with the hydrocarbon reaction that residue accumulation in equal facility if desired. If two or more halogens are the reaction eventually becomes static with no further present, a mixture of halogens can be used though it is buildup when the liquid and solid by-products are con preferred that the halogen be of the same element. tinuously recycled to successive runs.