3,463,840 United States Patent Office Patented Aug. 26, 1969 1. 2 phonates in small yields. When at least three moles of mer 3,463,840 captan are employed, the alkylthioalkyldithiophospho PROCESS FOR PRODUCING ALKYLTHOALKYL nates are obtained in good yields. PHOSPHONODTHOC ESTERS Alkylthioalkyldithiophosphonates are known com Marion F. Botts, Independence, Mo., and Erik K. Regel, Mission, Kans, assignors to Chemagro Corporation, pounds and are useful as defoliants, Regal patent 3,193,- New York, N.Y., a corporation of New York 372. The procedure for preparing such compounds in the No Drawing. Original application June 24, 1966, Ser. No. Regal patent, namely reacting PCls with a hydrocarbon 560,097. Divided and this application Jan. 3, 1968, Ser. and a disulfide in the presence of a Friedel-Crafts catalyst, No. 708,745 however, is relatively expensive considering the overall Int, Cl, C07f 9/40, A01n 9/36 O yields and reaction conditions employed. U.S. C. 260-972 8 Claims Accordingly, it is an object of the present invention to develop a novel method for making alkylthioalkyldithio phosphonates. ABSTRACT OF THE DISCLOSURE Another object is to develop a novel method for Compounds are prepared having the formula 5 making analogues of alkylthioalkyldithiophosphonates wherein the alkyl thio group is replaced by haloalkylthio. O SR3 A further object is to develop a method of preparing RSCIP N dithiophosphonates which cannot be synthesized by other R SR4 routes. where R, Ra, and R4 are alkyl or monohaloalkyl and R2 20 An additional object is to develop a novel method for is hydrogen, alkyl, monohaloalkyl, aryl, haloaryl or al killing nematodes. Still further objects and the entire scope of applica kylthioalkyl by (1) reacting 1 mole of phosphorus tri bility of the present invention will become apparent from chloride with one mole of an aldehyde having the formu the detailed description given hereinafter; it should be la RCHO at a temperature below 0° C., and (2) re 25 understood, however, that the detailed description and acting this product with 3 moles of a mercaptain or mixture specific examples, while indicating preferred embodi of mercaptains having the formula RSH, RSH and RASH ments of the invention, are given by way of illustration at a temperature below 0°C. The compounds are useful only, since various changes and modifications within the as nematocides. spirit and scope of the invention will become apparent 30 to those skilled in the art from this detailed description. This application is a division of our copending appli It has now been found that these objects can be at cation, Ser. No. 560,097, filed June 24, 1966. tained by preparing compounds having the following for The present invention relates to the preparation of alkyl mula: thioalkylphosphonodithioates and the use of Such com 3 5 pounds as nematocides. Risch (SR. The reaction of aldehydes whith phosphorus trichloride N has been investigated by several authors, e.g., Fossek, R SR4 II Monatshefte vol. 5, page 121 (1884), Kabashnik et al., where R1, R3 and R4 are alkyl (including cycloalkyl) and Chem. Abst. vol. 44, page 7257 (1950), and Conant et al., 40 haloalkyl and R2 is hydrogen, alkyl, monohaloalkyl, aryl, Jour. Amer. Chem. Soc., vol. 42, page 2337, vol. 43, pages haloaryl, and alkylthioalkyl. Preferably R1, Ra and R4 do 1928 and 10191, vol. 44, page 2530 and vol. 46, page 192. not have over six carbon atoms. Phosphorus trichloride adds on to aldehydes in an eXo Examples of compounds suitable as nematocides with thermic reaction at temperatures below 0° C., e.g., -50 in the invention are C. to -70° C. The products obtained are thermally un 45 S.S.-diethyl ethylthiomethane dithiophosphonate, stable and are in equilibrium with phosphorus trichloride S.S.-dimethyl 1-methylthio ethane dithiophosphonate, and aldehydes. The products have the formula: S.S.-diethyl 1-ethylthioethane dithiophosphonate, S.S.-dipropyl 1-propylthioethane dithiophosphonate, RCH-P Clah -- Cl N / S.S.-dibutyl 1-butylthioethane dithiophosphonate, O 50 S.S.-dicyclohexyl 1-cyclohexylthioethane dithiophos I phonate, where R is the residue of the aldehyde beyond the first S.S.-dimethyl 1-methylthiopropane dithiophosphonate, carbonation. S.S.-diethyl 1-ethylthiopropane dithiophosphonate, This addition product, however, easily reacts with mer S.S.-dipropyl 1-propylthio propane dithiophosphonate, captans. There are various possible competing reactions, 55 SS-dimethyl 1-methylthiobutane dithiophosphonate, including the following: S.S.-diethyl 1-ethylthiobutane dithiophosphonate, S.S.-dihexyl 1-hexylthiobutane dithiophosphonate, (a) mercaptal formation; S.S.-dimethyl 1-methylthio 2-ethylhexane dithiophos (b) trithiophosphite formation; phonate, (c) reaction of the mercaptain with the addition product. 60 S.S.-diethyl 1-ethylthio 3-chlorobutane dithiophosphonate, It has now been found that at temperatures well be S,S-diethyl 1-ethylthio 2-ethylthiobutane dithiophos low 0° C., e.g., -70 to -50 C., reaction (c) is the phonate, predominant reaction. S.S.-dimethyl 1-methylthio phenylmethane dithiophos When mercaptains are reacted with a compound of phonate, Formula I in a 1:1 mole ratio, the expected ox-chloroalkyl 65 S.S.-diethyl 1-ethylthiophenylmethane dithiophos chloridophosphonothioates could not be isolated. phonate, In similar fashion, when two moles of mercaptain Were S.S.-dibutyl 1-butylthio phenylmethane dithiophosphonate, reacted with a compound of Formula I, the expected ov S,S-diethyl 1-ethylthiop-chlorophenylmethane dithio alkylthioalkylchloridophosphonothioates could not be iso phosphonate, lated. 70 S.S.-diethyl propylthio methane dithiophosphonate, Instead, whether one mole or two moles of mercaptain S.S.-diethylbutylthiomethane dithiophosphonate, were used, there was isolated only alkylthioalkyldithiophos S.S.-dibutyl ethylthiomethane dithiophosphonate, 3,463,840 3 4. S.S.-dibutylbutylthiomethane dithiophosphonate, formed the mercaptal instead under the described reac S.S.-di (3-chloropropyl) 1-(3' chloropropylthio)ethane tion conditions. dithiophosphonate, The present invention is suitable for preparing dithio S.S.-diethyl 1-ethylthio 3-chloropropane dithiophos phosphonates which cannot be synthesized by other phonate, routes or which can be synthesized only with difficulty by S.S.-dimethyl 3-ethylthio propane dithiophosphonate, other methods. S.S.-dimethyl-1-methylthio-m-bromophenylmethane The reaction of the aldehyde with mercaptain can be dithiophosphonate, carried out in the presence of a solvent, e.g. benzene, S.S.-diamyl 1-amylthio o-chlorophenylmethane dithio toluene, carbon tetrachloride, chloroform or the like al phosphonate, though this is not essential. S.S.-diisopropyl -isopropylthiop-tolylmethane dithio O The general procedure employed to prepare the alkyl phosphonate, thioalkyl dithiophosphonates was as follows: S.S.-diethyl 1-ethylthio 2-methylpropane dithiophos phonate, GENERAL PROCEDURE S.S.-dimethyl 1-methylthio 2,6'-dichlorophenylmethane 5 Phosphorus trichloride was placed in a three necked dithiophosphonate, flask equipped with a thermometer, stirrer, condenser and S.S.-dimethyl-1,3-di(ethylthio) propane dithiophos dropping funnel. External cooling was provided by an phonate. acetone-Dry Ice bath. At -70° C. the aldehyde was added As aldehydes for the reaction, there can be used slowly while agitating the phosphorus trichloride. The formaldehyde (including trioxane and paraformalde 20 temperature was kept at -70° C. by adjusting the addi hyde), tion rate of the aldehyde. After addition of the aldehyde acetaldehyde, was completed the reaction mixture was agitated for 1 propionaldehyde, hour at -70° C. butyraldehyde, Then the mercaptain was added dropwise at -70° C. isobutyraldehyde, 25 to -60 C. The reaction mixture was then allowed to valeraldehyde, Warm up to -40° C. where hydrogen chloride began to hexaldehyde, evolve, and the reaction mixture was agitated for 1 hour 3-methylthio propionaldehyde, after the addition was completed. 2-ethylhexanal, Finally the reaction mixture was slowly brought up to 2-chlorobutyraldehyde, 30 room temperature and without agitation allowed to stand 3-chlorobutyraldehyde, for several hours. The crude product was then washed 2-ethylthiobutyraldehyde, with water until neutral, dried and distilled in a high benzaldehyde, WaC. 2-butylthioacetaldehyde, In order to separate small amounts of mercaptals from p-chlorobenzaldehyde, 35 the desired dithiophosphonate, the crude product is pref o-chlorobenzaldehyde, erably redistilled or fractionated over a small Vigreaux m-bromobenzaldehyde, column. 2,6-dichlorobenzaldehyde, Example 1 3-ethylthiopropionaldehyde, Using the General Procedure 1 mole (137.39 grams) 3-chloropropionaldehyde, 40 of phosphorus trichloride was reacted with 30 grams of p-tolualdehyde, paraformaldehyde (equivalent to 1 mole of formalde o-tolualdehyde, hyde). There was then added dropwise 3 moles (186 2,4,6-trichlorobenzaldehyde, grams) of ethyl mercaptan. The product was S.S.-diethyl 3-ethylthiopropionaldehyde. ethylthiomethane dithiophosphonate B.P., 120° C., n25 As mercaptains there can be used methyl mercaptain, 45 1.5652, Code No. 6480, yield 19%. ethyl mercaptan, propyl mercaptan, butyl mercaptain, Example 2 amyl mercaptan, cyclohexyl mercaptan, 3-chloropropyl The same product as that of Example 1 was prepared mercaptain, isobutyl mercaptan, secondary butyl mercap by an alternate procedure, namely, reacting 1 mole of tan, octyl mercaptan, 2-chlorobutyl mercaptan, 3-bromo 50 Sodium ethyl mercaptide with 1 mole of S,S-diethyl butyl mercaptain. chloromethane diethiophosphonate, filtered to remove so If a mixture of mercaptains are employed for reaction dium chloride and washed with water to produce S.S.-di with the aldehyde the product obtained in Formula II ethyl ethylthiomethane dithiophosphonate, B.P.o.o. 123 will be a mixture in which R, R and R4 need not be C., n° 1.5646. This product was given the Code No. alike. However, if a single mercaptain is used, then R1, 55 R and R will be identical. R2 in the formula is de 6435 and was obtained in a yield of 29%. pendent upon the aldehyde employed. Example 3 The preparation of alkylthioalkyl dithiophosphonates Using the General Procedure 1 mole of phosphorus by the reaction of at least three moles of mercaptain with trichloride was reacted with 1 mole of acetaldehyde. There 1 mole of aldehyde gives patricularly good yields with 60 was then added 3 moles of methyl mercaptan. The prod lower aliphatic aldehydes having at least two carbon uct was S.S.-dimethyl methylthioethane dithiophosphonate atoms, the yields in some cases exceeding 80%. Aromatic B.P.004. 110° C., no? 1.5996, Code No. 6483, yield in ex aldehydes also have been found to give good yields of cess of 70%. the desired product and monohalo aliphatic aldehydes Example 4 have been found to give yields up to 60%. 65 While more than 3 moles of mercaptain, e.g. 4, 5 or 6 Using the General Procedure 1 mole of phosphorus tri moles, can be used per mole of aldehyde there generally chloride was reacted with 1 mole of acetaldehyde. There is no advantage in doing so and the excess mercaptain must was then added dropwise 3 moles of ethyl mercaptan. be recovered. The product was S.S.-diethyl ethylthioethane dithiophos The yields of the alkylthioalkyl dithiophosphonates us phonate, B.P.o.o. 119 C., n25 1.5568, Code No. 6482, ing formaldehyde as the aldehyde generally are low. This 70 yield 70%. is also the case when employing alkylthio aliphatic alde Example 5 hydes, e.g. 3-ethylthiobutanal. Using the General Procedure 1 mole of phosphorus tri The reaction does not work with aldehydes having chloride was reacted with 1 mole of acetaldehyde. There o,6-aliphatic unsaturation. Chloral was inoperative and 5 was then added dropwise 3 moles of propyl mercaptan. 3,463,840 5 6 The product was SS-dipropyl propylthioethane dithio mercaptan. The product was S.S.-diethyl 1-ethylthio 3 phosphonate, B.P.o.o. 132° C., n25 1.5385, Code No. ethylthiobutane dithiophosphonate (also called S.S.-di 6443, yield 65%. ethyl 1,3 - di(ethylthio) butane dithiophosphonate), Example 6 B.P. 169 C., n25 1.5580. Code No. 6477, yield 22%. Using the general Procedure 1 mole of phosphorus tri Example 16 chloride was reacted with 1 mole of acetaldehyde. There Using the General Procedure 1 mole of phosphorus tri was then added dropwise 3 moles of butyl mercaptan. The chloride was reacted with 1 mole of benzaldehyde. There product was S.S.-dibutyl butylthioethane dithiophospho was then added dropwise 3 moles of methyl mercaptan. nate, B.P.o. 155° C., n25 1.5283, Code No. 6438, The product was S.S.-dimethyl 1-methylthio phenyl-me yield 68%. O Example 7 thane dithiophosphonate, M.P. 90° C., Code No. 6516. Using the General Procedure 1 mole of phosphorus tri Example 17 chloride was reacted with 1 mole of acetaldehyde. There Using the general Procedure 1 mole of phosphorus tri was then added dropwise 3 moles of cyclohexyl mercap chloride was reacted with 1 mole of benzaldehyde. There tan. The product was SS-dicyclohexyl cyclohexylthio 5 was then added dropwise 3 moles of ethyl mercaptan. The ethane dithiophosphonate, a high boiling oil, n25 1.5692, product was S.S.-diethyl 1-ethylthio phenylmethane dithio Code No. 6513, yield 82%. phosphonate, B.P.o.o. 170° C., n. 1.6015, Code No. Example 8 6450, yield 30%. 20 Example 18 Using the General Procedure 1 mole of phosphorus tri Using the General Procedure 1 mole of phosphorus tri chloride was reacted with 1 mole of propionaldehyde. chloride was reacted with 1 mole of benzaldehyde. There There was then added 3 moles of methyl mercaptan. The was then added dropwise 3 moles of butyl mercaptan. The product was S.S.-dimethyl 1-methylthiopropane dithio product was SS-dibutyl 1-butylthio phenylmethane di phosphonate, B.P.s 120° C., n25 1.5850, Code No. 25 thiophosphonate, a heavy oil n°81.5563, Code No. 6517, 6514, yield 33%. yield 94%. Example 9 Example 19 Using the General Procedure 1 mole of phosphorus tri Using the General Procedure 1 mole of phosphorus tri chloride was reacted with 1 mole of propionaldehyde. chloride was reacted with 1 mole of p-chlorobenzalde There was then added dropwise 3 moles of ethyl mercap 30 hyde. There was then added dropwise 3 moles of ethyl tan. The product was S.S.-diethyl 1-ethylthiopropane di mercaptan. The product was SS-diethyl 1-ethylthiop-chlo thiophosphonate, B.P.o.o. 120 C., n25 1.5536, Code No. rophenylmethane dithiophosphonate, B.P., 170° C., in 6518, yield 30%. Example 10 1.6048, Code No. 6921. 35 Example 20 Using the General Procedure 1 mole of phosphorus tri chloride was reacted with 1 mole of propionaldehyde. Using the General Procedure 1 mole of phosphorus tri There was then added dropwise 3 moles of propyl mercap chloride was reacted with 1 mole of acetaldehyde. There tan. The product was S.S.-dipropyl 1-propylthiopropane di was then added dropwise 3 moles of 3-chloropropyl mer thiophosphonate, B.P.o.o. 140 C., n. 1.5363, Code No. 40 captan. The product was S.S.-di (3'-chloropropyl) 1,3'- 6519. chloropropylthioethane dithiophosphonate, a heavy oil, Example 11 Code No. 6444. Using the General Procedure 1 mole of phosphorus tri Example 21 chloride was reacted with 1 mole of butyraldehyde. There Using the General Procedure 1 mole of phosphorus tri was then added dropwise 3 moles of methyl mercaptain. chloride was reacted with 1 mole of 3-ethylthio propion The product was S.S.-dimethyl 1-methylthiobutane dithio 45 aldehyde. There was then added 3 moles of methyl mer phosphonate, B.P.o.o. 120° C., n25 1.5700, Code No. captan. The product was S.S.-dimethyl 1-methylthio 3-eth 6515, Yield 20%. ylthiopropane dithiophosphonate, a heavy oil, Code No. Example 12 6445. Example 22 Using the General Procedure 1 mole of phosphorus 50 trichloride was reacted with 1 mole of butyraldehyde. The procedure of Example 3 was repeated. The product There was then added dropwise 3 moles of ethyl mercap was given the Code No. 6436. tan. The product was S.S.-diethyl 1-ethylthiobutane dithio Example 23 phosphonate, B.P.o.o. 130 C., no 1.5475, Code No. 6440, yield 50%. 55 The procedure of Example 4 was repeated. The product Example 13 was given the Code No. 6437. Using the General Procedure 1 mole of phosphorus tri Example 24 chloride was reacted with 1 mole of 2-ethylhexanal. The procedure of Example 9 was repeated. The product There was then added 3 moles of methyl mercaptan. The product was S.S.-dimethyl 1-methylthio-2-ethyl-hexane di 60 was given the Code No. 6439. thiophosphonate, B.P.o.o. 128 C., n25 1.5478, Code No. Example 25 6441, yield 13%. Using the General Procedure 1 mole of phosphorus tri Example 14 chloride was reacted with 1 mole of 3-chlorpropionalde Using the General Procedure 1 mole of phosphorus tri 65 hyde. There was then added dropwise 3 moles of ethyl chloride was reacted with 1 mole of 3-chlorobutyralde mercaptan. The product was S.S.-diethyl 1-ethylthio 3 hyde. There was then added dropwise 3 moles of ethyl chloropropane dithiophosphonate, a heavy oil, Code No. mercaptan. The product was S.S.-diethyl 1-ethylthio-3- 6475. chlorobutane dithiophosphonate, B.P.o.o. 145 C., ind' Example 26 1.5550, Code No. 6476, yield 22%. 70 1 mole of sodium propyl mercaptide was reacted with 1 mole of S.S.-diethyl chloromethane dithiophosphonate using Example 15 the procedure of Example 2 to produce S.S.-diethyl propyl Using the General Procedure 1 mole of phosphorus tri thiomethane dithiophosphonate as an oil, Code No. 6470. chloride was reacted with 1 mole of 3-ethylthiobutyral Alternatively, Code No. 6470 can be prepared in low dehyde. There was then added dropwise 3 moles of ethyl 75 yields by the General Procedure reacting 1 mole of phos 3,463,840 7 8 phorus trichloride with 30 grams of paraformaldehyde (1. 18 carbon atoms in the alkyl group, alkyl-phenol-ethylene mole of formaldehyde) followed by the dropwise addition Oxide condensation products, e.g., p-isooctylphenol con of a mixture of 2 moles of ethyl mercaptain and 1 mole densed with 10 ethylene oxide units, soaps, e.g., sodium of propyl mercaptan. Stearate and potassium oleate, sodium salt of propylnaph Example 27 thalene sulfonic acid, (di-2-ethyl hexyl) ester of sodium SulfoSuccinic acid, sodium lauryl Sulfate, sodium salt of 1 mole of sodium butyl mercaptide was reacted with 1 the sulfonated monoglyceride of cocoanut fatty acids, mole of S,S-diethyl chloromethane dithiophosphonate us sorbitan sesquioleate, lauryl trimethyl ammonium chlo ing the procedure of Example 2 to produce S.S.-diethyl bu ride, octadecyl trimethyl ammonium chloride, polyethyl tylthiomethane dithiophosphonate as an oil, Code No. O ene glycol lauryl ether, polyethylene esters of fatty acids 6471. and rosin acids, e.g., Ethofat 7 and 13, sodium N-methyl Alternatively, Code No. 6471 can be prepared in low N-oleyl-taurate, Turkey red oil, sodium dibutylnaphtha yields by the General Procedure reacting 1 mole of phos lene sulfonate, sodium lignin sulfonate (Marasperse N), phorus trichloride with 30 grams of paraformaldehyde polyethylene glycol stearate, sodium dodecylbenzene sul followed by the dropwise addition of a mixture of 2 moles 5 fonate, tertiary dodecyl polyethylene glycol thioether of ethyl mercaptain and 1 mole of butyl mercaptan. (Nonionic 218), long chain ethylene oxide propylene oxide condensation products, e.g., Pluronic 61, sorbitan Example 28 monolaurate, polyethylene glycol ester of tall oil acids, 1 mole of sodium ethyl mercaptide was reacted with 1 Sodium octylphenoxyethoxyethyl sulfate, tris (polyoxy mole of S.S.-dibutyl chloromethane dithiophosphonate us 20 ethylene) sorbitan monostearate (Tween 60), sodium di ing the procedure of Example 2 to produce S.S.-dibutyl hexyl sulfosuccinate. ethylthiomethane as an oil, Code No. 6472. The solid and liquid formulations can be prepared by Alternatively, Code No. 6472 can be prepared in low any of the conventional methods. Thus, the active ingredi yields by the General Procedure reacting 1 mole of phos ent can be mixed with the solid carrier in finely divided phorus trichloride with 30 grams of paraformaldehyde fol 25 form in amounts small enough to preserve the free-flowing lowed by the dropwise addition of a mixture of 2 moles property of the final dust composition. butyl mercaptain and 1 mole of ethyl mercaptain. In commercial practice the compositions containing the nematocides of the present invention are applied to the Example 29 soil infested with nematodes. 1 mole of sodium butyl mercaptide was reacted with 30 In the following examples or tables illustrating nema 1 mole of SS-dibutyl chloromethane dithiophosphonate tocidal activity the compounds of the invention were using the procedure of Example 2 to produce S.S.-dibuty formulated as wettable powders consisting of 50% of the butylthiomethane dithiophosphonate as an oil, Code No. compound being tested, 46% Hi-Sil 233 (ultrafine silica), 6473. 2% Marasperse N (sodium lignin sulfonate) and 2% Alternatively, Code No. 6473 can be prepared in low 35 Pluronic L-61 (polyethylene oxide-propylene oxide ad yields by the General Procedure reacting 1 mole of phos duct molecular weight about 1000). This wettable powder phorus trichloride with 30 grams of paraformaldehyde fol is hereinafter designated as Formulation A. lowed by the dropwise addition of 3 moles of the butyl Example 30 mercaptain. The compounds of the present invention can be used 40 The saprophytic nematode tests were carried out in alone as nematocides but it has been found desirable to water as the medium with Panagrellus and Rhabditis spp. apply them to the pest, e.g. to the soil habitat of nema at room temperature utilizing Formulation A. The results todes, together with inert solids to form dusts, or, prefer are recorded as percent kill at the indicated dosages in ably water. There can also be added surface active agents parts per million after a 4 day incubation period. A 10% and inert solids in such liquid formulations. Desirably, 45 kill is merely the same amount of kill as occurs with a 0.05 to 1% by weight of surface active agent is employed. blank sample. The active ingredient can be from 0.01 to 95% by weight TABLE I of the entire composition in Such cases. In place of water there can be employed organic Sol NESA at p.p.m. vents as carriers, e.g., hydrocarbons such as benzene, tolu 50 Compound Example 00 50 O ene, xylene, kerosene, diesel oil, fuel oil, and petroleum 6485------80 30 10

6480------2 80 30 O naphtha, ketones such as acetone, methyl ethyl ketone and 26 OO 50 O cyclohexanone, alcohols, e.g., ethanol, isopropanol and 27 100 50 O 28 00 50 10 amyl alcohol, etc. 29 00 50 O 22 OO 00 OO The nematocides of the present invention can also be 23 80 50 O applied with inert nematocidal adjuvants or carriers Such 5 00 80 50 as talc, pyrophyllite, synthetic fine silica, Attaclay, kiesel 20 100 80 30 6 50 10 O guhr, chalk, diatomaceous earth, lime, calcium carbonate, 24 50 10 10 2 00 50 O bentonite, fuller's earth, cottonseed hulls, wheat flour, 3. 30 10 O soybean flour, pumice, tripoli, wood flour, walnut shell 6 25 50 O O 17 50 0 10 flour, redwood flour and lignin. 2. 80 50 10 It is frequently desirable to incorporate a surface active 3 80 80 50 4. 30 10 O agent in the pesticidal compositions of this invention. Such 7 30 O O surface active agents, i.e., wetting agent, are advanta 8 00 100 30 00 OO 30 geously employed in both the solid and liquid composi 6 80 80 50 tions. The surface active agent can be anionic, cationic 18 80 50 30 or nonionic in character. 9 OO 00 80 Typical classes of surface active agents include alkyl 10 00 00 80 sulfonate salts, alkylary sulfonate salts, alkyl Sulfate salts, alkylamide sulfonate salts, alkylary polyether alco 70 Example 31 hols, fatty acid esters of polyhydric alcohols and the Some of the compounds were also tested against para alkylene oxide addition products of such esters, and addi sitic nematodes employing Formulation A. The nematode tion products of long chain mercaptains and alkylene employed was Meloidogyne spp. and the procedure was oxides. Typical examples of such surface active agents a 10 day contact test carried out in a water-agar medium include the sodium alkyl benzene sulfonates having 14 to 75 in the presence of tomato roots at room temperature. 3,463,840 9 10 The results are given on a 0-10 scale where 0 indicates or mixture of mercaptains having the formula RSH, the presence of severe knotting, i.e. no effectiveness and RSH and RASH at a temperature not over -40° C. 10 indicates no knots, i.e. 100% effectiveness. The dosages 2. A process according to claim 1 wherein reactions are at the indicated concentrations of test compound in (1) and (2) are carried out at a temperature between parts per million. -70 C, and -40 C. TABLE II 3. A process according to claim 2 wherein reactions (1) and (2) are carried out at a temperature between NEMA at p.p.m. -70° C. and -50° C., R1, R3 and R4 are lower alkyl Compound Example 50 25 2 6 and R2 is alkyl of 1 to 3 carbon atoms. 6480------2 O O 7, 6 5 O 4. A process according to claim 1 wherein R1, R3 and 6470------26 O O O 0 647. 27 O O O O R4 are the same. 6472. 28 8 O O O 5. A process according to claim 4 wherein reactions 6473. 29 5 O O 6436. 22 8,8 O O O (1) and (2) are carried out at a temperature between 6437 23 8.8 O 0 O -70' C. and -40 C. 6443. 5 0 O 8.8 5 6. A process according to claim 4 wherein R, R and 6439 24 8.8 0 O O R4 are lower alkyl. 6518. 9 O O O O 7. A process according to claim 6 wherein R2 is alkyl We claim: of 1 to 3 carbon atoms. 1. A process of preparing a compound having the 8. A process according to claim 6 wherein R is formula 20 phenyl. References Cited O SR3 Rischi^ UNITED STATES PATENTS N 2,254,124 8/1941 Stevens et al. -- 260-972 XR R SR4 3,346,669 10/1967 Regel ------260-972 XR where R1, R3 and R4 are lower alkyl, monochloro lower 25 alkyl or mono bromo lower alkyl and R2 is hydrogen, CHARLESB. PARKER, Primary Examiner lower alkyl, mono chloro lower alkyl, phenyl, chloro phenyl, bromophenyl, methyl phenyl or lower alkylthio A. H. SUTTO, Assistant Examiner alkyl comprising (1) reacting 1 mole of phosphorus tri chloride with one mole of an aldehyde having the for 30 U.S. C. X.R. mula RCHO at a temperature not over -40° C., and 260-936, 958, 961; 424-216 (2) reacting this product with 3 moles of a mercaptain