United States Patent (15) 3,691,217 McCann (45) Sept. 12, 1972

54) PROCESS FOR THE PREPARATION OF 2,525,723 10/1950 Rabjohn...... 260/544 ACYL CHLORDES AND BENZALDEHYDES Primary Examiner-Lewis Gotts (72) inventor: Thomas J. McCann, Brooklyn, N.Y. Assistantttorney-Janes Examiner-Catherine & Chapman. L. Mills 73 Assignee: Argus Chemical Corporation, Brook lyn, N.Y. (57) ABSTRACT 22 Filed: March 16, 1970 A catalytic process is provided for the preparation of (21) Appl. No.: 20,142 benzoyl chlorides and benzaldehydes comprising reacting benzo polychloromethanes with an organic carboxylic acid to produce the corresponding benzoyl 52 U.S. Cl...... 2601408, 260/544 L., 260/544M, chloride or benzaldehyde plus the acyl chloride cor 260/544 Y, 260/599, 260/966 responding to the organic carboxylic acid, the reaction 5ll int. Cl...... C11o 3/100 being carried out in the presence of a tin chloride 58) Field of Search...... 260/408, 544,599 catalyst. 56) References Cited 23 Claims, No Drawings UNITED STATES PATENTS 1921,767 8/1933 Mills...... 260/544 3,691,217 2 PROCESS FOR THE PREPARATION OF ACYL was used. Fumaric acid and benzotrichloride have been CHLORDES AND BENZALDEHYDES reacted in the absence of any catalyst at from 140 to 170° C to produce benzoyl chloride, according to U.S. Aroyl and acyl chlorides, such as benzoyl chloride Pat. No. 1,793,917 to Faber, dated Feb. 24, 1931. and acetyl chloride, are useful in medicine, and further British Pat. No. 1,148,782 prepares benzoyl chloride as intermediates in the manufacture of the correspond by the pressure reaction of benzoic acid with CCls in ing acids, peracids and esters. the presence of FeCla. The acid chlorides have generally been made by the British Pat. No. 1,159,266 describes the preparation reaction of phosphorus trichloride or pentachloride of acyl halides by the reaction of carboxylic acids with with a carboxylic acid. This reaction is favored com O phosgene in the presence of a quaternary ammonium, mercially because of the greater economy which can be phosphonium or ternary sulphonium salt. achieved in conversion and yield in relation to the cost Netherlands Pat. publication No. 68.14725 discloses of the reactants. However, phosphorus impurities the reaction of a carboxylic acid with hex should be removed from the reaction product, since achloropropene, forming the corresponding they can interfere with the use of the product, and this 15 acylchloride and trichloroacryloyl chloride. Suggested removal is not easy. Hence, efforts have been made to catalysts are ZnCl2, FeCls or I. develop a better process, but these have been unsuc McKee German Pat. No. 540,588 describes the cessful, except in the laboratory. preparation of fumaryl-and benzoyl chloride by the Benzoyl chloride can be prepared by the partial reaction of CHCCla and fumaric acid in the presence hydrolysis of benzo trichloride of ironpowder. None of these has been successful, because inter alia of the low yields and conversions generally obtained, {O-cci, and the resulting high cost and low purity of the to remove two chlorines and substitute carboxyl ox product. In some cases, the starting materials cost more ygen in the presence of sulfuric acid or a metal halide 25 than the reaction products, and in others the price dif such as ferric chloride (FeCl) and water. ferential is too small to justify the cost of the process. Benzotrichloride has also been partially hydrolyzed by In accordance with the present invention, it has now reacting at 240° C with water vapor in the presence of been discovered that the reaction of a benzo tin phosphate. See Huntress, Organic Chlorine Com polychloromethane with an organic carboxylic acid can pounds, John Wiley & Sons (New York, 1948), pp. be efficiently carried out in the presence of a tin halide, 880-88. to obtain the acid chloride corresponding to the car Jacobson, German Pat. No. 11494 (1879), describes boxylic acid and benzoyl chloride or benzaldehyde, in the reaction of benzotrichloride as well as of benza high yield and purity. The reaction can be carried out chloride and a carboxylic acid in the presence of ZnCl2, 35 at a lower temperature than with zinc chloride, and, as SbCl or CuCl, forming the corresponding acyl a result, there is less decomposition or degradation. chloride, and benzoyl chloride or benzoic acid or Reaction at the lower temperatures proceeds at a high benzaldehyde, respectively, according to the catalyst rate, and favors the formation of the acyl and benzoyl used. chlorides or benzaldehyde, while inhibiting formation U.S. Pat. Nos. 1963,748 and 1,963,749 to Kyrides, 40 of other by-products or tarry residues and suppressing patented Apr. 28, 1930, suggested that polyvalent al (as is particularly the case for ZnCl2 catalyst) the for kaline earth metal salts and especially the chlorides, ox mation of substantial amounts of anhydride. ides and hydroxides of zinc, aluminum, chromium and The reaction can be defined by the following copper, catalyzed the reaction of benzotrichloride with scheme: dicarboxylic acids or their anhydrides, such as phthalic 45 anhydride or phthalic acid to form benzoyl chloride, H among other things. / SnCly U.S. Pat. No. 1,921,767, to Mills, dated May 20, R(COOM) in + R' (6-m) - Ar c law» 1929, suggests that the chlorides of cobalt, antimony, Cl3-n-m2 copper and bismuth catalyze the reaction of 50 R(-C), -- R' (6-m) -T benzotrichloride and an aliphatic acid such as acetic () O n acid. U.S. Pat. No. 1,965,556, to Mills, dated July 3, 1934, discloses reaction of an aliphatic acid, such as acetic In the above formulas, acid, and benzotrichloride in the presence of zinc 55 R is a hydrocarbon group or a hydrocarbon group chloride at temperatures of from 100 to 110°C, to ob having one or more inert substituents, tain a mixture of benzoyl chloride and the correspond R" is selected from hydrogen, halogen, alkoxy, ing acetyl chloride. hydrocarbon, and hydrocarbon having one or German Pat. No. 804,567 (1951) describes prepara more inert substituents. tion of acyl halides by reacting lactones with non 60 Ar is a benzene ring, and can include one or more metallic polyhalogenated compounds, e.g., CshsCCl3 benzene rings linked by carbon-to-carbon bonds as or CHCHCl in the presence of catalysts, i.e., HSO, in diphenyl or by an inert bridging radical, ZnCl and FeCl or Zn dust. M is hydrogen or a salt-forming cation, Johnson, German Pat. No. 574,836 (1931), British X is hydrogen or chlorine, Pat. No. 384,722, French Pat. No. 739,290, prepare 65 m is a number from one to six and represents the sulphonic acid chlorides by reacting CHCCl3 with the number of -COOH groups, corresponding sulphonic acid sodium salt. No catalyst m is a number from one to six, 3,691,217 3 4 n is a number from zero to one, pyrrole-2-carboxylic acid, nicotinic acid, quinaldic y is two or four. acid, 3-butynoic acid, monoethyl adipate, isobutyl The process is applicable to organic carboxylic acids benzoic acid, ethylbenzoic acid, isopropylbenzoic acid, R(COOH) mi having from one to six carboxylic acid p-t-butylbenzoic acid, n-hexylbenzoic acid, g-naphtho groups, with not more than one carboxylic acid group ic acid, 6 -naphthalene acetic acid, orthobenzoyl per carbon atom, and having from two to about 51 car benzoic acid, naphthenic acids derived from petrole bon atoms. Thus, R has from one to about 50 carbon um, abietic acid, dehydroabietic acid, methyl furoic atomS. acid, thienoic acid, monochloroacetic acid, R is a saturated or unsaturated aliphatic, aromatic or bromoacetic acid, 2-bromoisovaleric acid, iodoacetic cycloaliphatic hydrocarbon group, such as alkyl, O acid, dichloro- and trichloroacetic acids, a - cycloalkyl, alkenyl, alkynyl, cycloalkyl, cyclokenyl, chloropropionic acid, B -chloropropionic acid, 6 - phenyl, biphenyl, naphthyl, benzyl, or phenethyl, or a chlorocaproic acid, and dodecyl thioether propionic heterocyclic group containing one or more nitrogen, acid (C12H2s-S-(CH2)2-COOH). oxygen or sulfur hetero atoms, singly or in combina Exemplary dicarboxylic acids include isophthalic tions, and such groups substituted with inert groups 15 acid, terephthalic acid, naphthalic acid, 3,5-pyridine such as halogen, oxyether or thioether groups, sulfonyl dicarboxylic acid, 3,5-quinoline dicarboxylic acid, groups, carbonyl groups, ester groups or nitro groups. adipic acid, pimelic acid, suberic acid, azelaic acid, Preferably, R has from one to 30 carbon atoms and one sebacic acid, glutaconic acid, octenedioic acid, un or two carboxylic acid groups. decanedioic acid, thiodipropionic acid, cyclohex The reaction proceeds preferentially with carboxylic 20 anel,4-dicarboxylic acid, and acetylene dicarboxylic acid groups that form noncyclic anhydride, acid halide acid. or aldehyde groups. Thus, if there are more than two The higher polycarboxylic acids include trimellitic carboxylic acid groups, of which two are capable of acid, 1,3,5-pentanetricarboxylic acid, 1,2,4-hexane forming a cyclic anhydride, and the others are not, the tricarboxylic acid, 5-octene-3,3,6-tricarboxylic acid, former carboxylic acid groups are substantially less 25 1,3,5-benzenetricarboxylic acid, and 1-(2-carbox reactive and the reaction proceeds preferentially with yethyl)-2,3-naphthalenediacetic acid. the latter carboxylic acid groups in the molecule which Metal salts (M is a salt-forming cation) of the organic do not form the cyclic anhydride, until these have been carboxylic acids are also reactive in this process, espe converted to acid halide groups. Hence, by limiting 30 cially the alkali metal salts such as sodium and potassi proportions of benzopolychloromethane, it is possible um, and the alkaline earth metal salts, such as calcium to limit the reaction to the latter. and barium. In this case, the reaction product is the R' is selected from hydrogen, halogen, alkoxy, satu metal chloride in place of hydrogen chloride; the metal rated or unsaturated aliphatic, aromatic or chloride precipitates out as a salt, rather than being ex cycloaliphatic hydrocarbon, such as alkyl, alkynyl, 35 pelled as a vapor overhead. cycloalkyl, alkenyl, alkylcycloalkyl, cycloalkenyl, The benzopolychloromethane has at least one six phenyl, biphenyl, naphthyl, benzyl, or phenethyl, or a membered carbocyclic aromatic ring, up to four such heterocyclic group containing one or more nitrogen, rings, and one or more of the rings can be substituted oxygen or sulfur hetero atoms, singly or in combina by an inert substituent or by additional tions, and such groups substituted with inert groups 40 polychloromethane groups (CCl3 and CHCl2). Thus, such as halogen, oxyether, thioether, sulfonyl, carbon the benzopolychloromethane has the formula: yl, ester or nitro groups. Preferably, R' has from one to 30 carbon atoms, when R' is an organic group. Examples of monocarboxylic acids include acetic acid, n-butyric acid, isobutyric acid, 3-nitropropionic 45 II. Hn / acid, cyano-acetic acid, n-butyric acid, isobutyric acid, R' (6-in-Ar- C n-valeric acid, n-hexanoic acid, 2-methyl hexanoic N acid, heptanoic acid, octanoic acid, 2-ethyl hexanoic Cl3-n-m2 acid, nonanoic acid, pentadecanoic acid, capric acid, undecanoic acid, lauric acid, myristic acid, palmitic 50 acid, caprylic acid, arachidic acid, palmitic acid, mar garic acid, stearic acid, stearolic, tetrolic, propiolic where Ar is the aromatic carbocyclic nucleus and R', acids, acrylic acid, crotonic acid, 3-methyl crotonic m2 and n are as in I, above. acid, isocrotonic acid, vinyl acetic acid, angelic acid, 3 Ar is usually a benzene ring butenoic acid, 3-hexenoic acid, 4-heptenoic acid, 5-oc 55 tenoic acid, 4-methylene-2-nonenoic acid, 2-ethylidene hexanoic acid, pentadecenoic acid, sorbic acid, arachidonic acid, linoleic acid, linolenic acid, benzoic acid, toluic acid naphthoic acid, 2,4-dimethylbenzoic but it can also have two or more linked benzene rings, acid, p-iodobenzoic acid, m-bromobenzoic acid, 2,4-, 2,5-, 2,6- or 3,4-dichlorobenzoic acid, 3,4,5- trifluorobenzoic acid, cyclohexane carboxylic acid, cycloheptane carboxylic acid, cyclobutane carboxylic " . . . ) acid, methyl cyclopropane carboxylic acid, 2-methyl and cyclohexane carboxylic acid, 2-norbornanecarboxylic 65 {D-( )-(D and in acid, phenyl acetic acid, phenylbutenoic acid, phenyl propanoic acid, cinnamic acid, phenyl propionic acid, {DYK D. 3,691,217 S 6 where Y is a linking nucleus, such as The reaction is preferably carried out under an hydrous conditions, to prevent hydrolysis of the reac tants or products. A dry inert atmosphere or other an hydrous atmosphere, such as nitrogen, preferably at a slight positive pressure above ambient, is therefore use ful to ensure against any leakage of moisture into the reaction system, Active sites, especially any ethylenic groups, or ester in being equal to the valence of Y, and being one or groups in carboxylic acid or on any substituent of the two. Ar. can also have condensed aromatic nuclei, as in O benzopolychlormethane are sometimes partially inaphthalene halogenated or hydrolyzed in the course of the reac tion, due apparently to reaction with hydrogen chloride liberated in the course of the reaction. To avoid this the 15 reaction is preferably carried out in the presence of an inert diluent or carrier, which increases the rate of and anthracene removal of hydrogen chloride from the reaction site. Optimally, the hydrogen chloride is removed substan tially as soon as it is formed, thus preventing any side reaction with the reactants or reaction product. The inert diluent should boil at a temperature and pressure and phenanthrene above or at that at which the reaction is carried out, and is preferably a solvent for the reactants. Examples of inert solvents include trichloroethane, 25 perchlorethylene, octane, petroleum ether, naphtha, methylcyclohexane and dioxane, benzene and toluene. Alternatively, or in addition, a dry inert gas, such as dry nitrogen gas, can be used as a sweep, to aid in the removal of hydrogen chloride. The polychloromethane group has two or three 30 The reaction can be carried out by heating the reac chlorine atoms, and is either -CHCl or -CCl3 tion mixture under reflux, especially when the material Each polychlormethane side-chain can react with an being reacted includes an ethylenic bond or ester group active carboxyl group in the organic carboxylic acid, so which is susceptible to reaction with the hydrogen that the stoichiometric quantities of each of the reac chloride evolved during the reaction process. The use tants are determined by the number of such active 35 groups present in each molecule that is to be reacted. of a solvent under reflux acts as a sweep to speed up the Examples of benzopolychloromethanes include 3 removal of the hydrogen chloride, generally removing methylbenzotrichloride, 2,5-dimethyl the hydrogen chloride as it is formed. The solvent and benzotrichloride, 4-butyl-benzotrichloride, 4,4'-ox any reactant or product that volatilizes are condensed ybis(benzotrichloride, 4,4'-carbonyl 40 under reflux and returned to the reaction mixture. The bis(benzotrichloride), 4,4'-sulfonyl HCl is not condensed but is removed as vapor. Any bis(benzotrichloride), 2-propyl-benzotrichloride, 2-(3- product distilled off can be condensed and removed at butenyl)-benzotrichloride, 4-phenyl-benzotrichloride, this stage. This is especially useful in a continuous 2-methyl-4-trichloromethyl-benzotrichloride, 4 process. chlorobenzotrichloride, 3-bromobenzotrichloride, 4 45 The amount of inert solvent present should be methoxy-benzotrichloride 2-bronomethyl enough to act as a sweep and can be within the range benzotrichloride, 4-cyclohexylbenzotrichloride, 4 from about 5 to about 70 percent by weight of the reac nitrobenzoylidenechloride, 3,5-trichloromethyl tion mixture. benzotrichloride, 3-trichloromethylethylbenzoate, The reaction will generally be completed at the benzylidene chloride, 4-t-butylbenzylidene chloride, 50 preferred temperatures within from about 1 to about 3 tri(dichloromethylphenyl) phosphate, and 2-acetox hours; usually from 1 to 3 hours is sufficient to obtain at ybenzylidenechloride. Mixtures of -CHCl, and-CCl3 least an 80 percent yield of the desired acyl chloride. compounds such as those resulting from the side-chain The reactants can be added in stoichiometric quanti chlorination of xylene with three to six moles of 5 ties. However, an excess of either of the reactants is not chlorine, can be used without separation. 5 detrimental. The process can be carried out as a batch The reaction should be carried out at a temperature processor as a continuous process, where the reactants high enough to initiate the reaction and maintain the are continuously fed and the reaction products are con reaction at the desired rate, but below the degradation tinuously removed from the reaction system. temperature of any of either the reactants or the If a metal salt of the organic carboxylic acid is a reac products of this process. Generally, the temperature is 60 tant, the by-product is the metal chloride, instead of within the range from about 40 to about 170° C., and hydrogen chloride, and the metal chloride precipitates preferably from about 80° to about 140°C. from the reaction mixture. Although the solid metal Pressure has no noticeable effect. Hydrogen chloride chloride is removed in an additional separation step, is liberated and volatilizes at atmospheric pressures at e.g., filtration or decantation, the salt can be especially the temperature at which the reaction proceeds, unless 65 useful with very sensitive unsaturated compounds or salt formation prevents this. A vacuum withdrawal esters, to avoid halogenation or hydrolysis of the system is unnecessary, but can be used if desired. products by HCl. 3,691,217 7 8 If the polychloromethane reactant is a benzotrichloride, the product of this reaction can be a The reaction vessel was heated to 110° C. and main mixture of two acyl chlorides: one, the aroyl chloride tained at that temperature for 1.5 hours. The reaction corresponding to the benzotrichloromethane, e.g., mixture was then fractionated using a 0.5 ft. Vigreux benzoyl chloride; the second, the acyl chloride cor column. responding to the organic carboxylic acid, e.g., lauroyl At a pot temperature of 84 C. was an overhead chloride. A single reaction product is obtained when vapor temperature of 74 C. at 12 mm pressure, a the carboxylic acid has the same organic group as is forerun of 20 grams was collected, comprising SnCl4 present in the benzotrichloride. For example, the reac and benzoyl chloride. At a pot temperature of 86 to tion between benzotrichloride and benzoic acid yields 10 129°C. with a vapor temperature of 75° to 98° C. and benzoyl chloride. If the benzopolychloromethane is a 12 mm pressure, 685.7 grams of benzoyl chloride was benzylidene chloride, the reaction with the carboxylic collected. A third fraction was collected at a pot tem acid yields the benzaldehyde and the carboxylic acid perature of 134 to 139 C. and a vapor temperature of chloride. 128° to 132C., consisting of 1041.4 grams of lauroyl Generally, when a mixture of materials is formed, 15 chloride. A tarry residue, 55 grams, remained in the e.g., as in the reaction between lauric acid and reaction flask. benzotrichloride to form a mixture of lauroyl chloride The yield of benzoyl chloride was 705 grams, and of and benzoyl chloride, the products can be separated to lauroyl chloride was 1,080 grams. Thus, a yield of 96.5 obtain the individual compounds. Usually, this can 20 percent of theory for lauroyl chloride and of 97.5 per most readily be accomplished by fractional distillation, cent for benzoyl chloride was realized. especially if the boiling points of these two products are relatively far apart. A sufficient range of starting EXAMPLE 2 materials is available so that for any desired acyl A reaction flask equipped as in . Example l, was chloride or aldehyde the reactants for this process can 25 charged with 700 grams (5 mols) toluic acid, 990 be selected to form acyl chlorides whose boiling points grams (5.05 mol, l percent excess by weight) are sufficiently far apart to make it possible to carry out benzotrichloride, and 10.3 grams (0.04 mol) SnCl the separation by fractional distillation. For example, The flask was heated to 100° C., and held at that tem mixtures of benzotrichloride and lauric acid or perature for 1.5 hours. The reaction mixture was then benzotrichloride and adipic acid both form mixtures of vacuum distilled at 19 mm. reaction products that can be readily separated by frac A forerun of 50.5 g. was collected at a pot tempera tional distillation. 2-Ethylhexanoic acid and p-t-butyl ture of 104°C. to 106° C. and a vapor temperature of benzotrichloride are another convenient pair of reac 100° C. which was primarily SnCl4 and benzoyl tants for easy separation by distillation. Of course, chloride. The main cut collected at a pot temperature where a mixture of the two acyl chlorides can be 35 of 106 to 123° C., and a vapor temperature of 100 to tolerated, e.g., toluyl chloride and benzoylchloride, 117 C. comprised 1,393 grams of a mixture of benzoyl separation is unnecessary. and toluyl chloride; approximately 664 grams The tin chloride that is added can be either stannic or benzoylchloride (4.72 mols), and 728 grams toluyl stannous chloride. It is believed that the actual catalyst chloride (4.72 mols). is stannic chloride, but that under the conditions of the 40 This represents yields of 94 percent for toluyl reaction mixture, any stannous chloride is oxidized to chloride as well as 94 percent for benzoyl chloride. Ap the stannic chloride, which then serves as the catalyst proximately 57.8 grams of residue remained. for the reaction. In any case, either of these is effective. The tin chloride, i.e., SnCl, or SnCl4, is preferably in EXAMPLE 3 a catalytic amount within the range from about 0.1 to 45 about 2.5 percent, based on the total weight of the To a three-necked 500 ml. flask equipped as above reactants. However, more than 2.5 percent tin chloride was added 147 grams benzotrichloride (0.75 mol), does not usually affect the course of the reaction, and 91.5 grams benzoic acid (0.75 mol) and 5.9 grams 10 percent or more can be used (although it is unneces SnCl4 (0.02 mol). The flask was heated to about 130 sary) unless tar formation is increased. 50 C., and held at that temperature for 1.5 hours. The In the following working Examples, the products hydrogen chloride evolution in this case began at room were analyzed by gas-liquid chromatography and, un temperature, and halted before the 1.5 hours had less otherwise stated, the reaction products isolated passed. The reaction mixture was then distilled at 20 were free from any of the reactants, indicating mm pressure at a pot temperature of 90 to 93 C.; the complete conversion of the reactants. 55 distillate consisted of 207.5 grams of benzoyl chloride, The following Examples represent preferred embodi which is a yield of approximately 98.5 percent. ments of this invention. EXAMPLE 4 EXAMPLE 1. To a three-necked 500 ml. glass flask was added 60 decanoic acid, 86 grams (0.5 mol); benzotrichloride, The following reaction mixture was charged to a 97.75 grams (0.5 mol); and SnCl4, 1.3 grams (0.005 three-necked, 5-liter, round-bottom flask, equipped mol). The flask was heated to 100° C. and held there with a mechanical stirrer, thermometer and a reflex for 1.5 hours; the reaction mixture was then distilled condenser: through a 0.5 ft. Vigreux column, at 10 to 15 mm, using 65. the procedures set forth above. The product comprised Lauric acid 1001.5 g. (5.0 mols) Benzotrichloride 9900 g. (5.05 mols) 91 grams benzoyl chloride and 91 grams of decanoyl SnCl 10.3 g. (0.04 mol) chloride, representing a yield of 100 percent for the 3,691,217 9 10 benzoyl chloride and 96 percent for the decanoyl substantially quantitatively reacted with a chloride. benzotrichloride, to the exclusion of the cyclic an hydride groups, which behave as though they were in EXAMPLE5 et. The procedure of Example 1 is repeated substituting 5 an equivalent molar amount of cyclohexane carboxylic EXAMPLE | 1 acid in place of the lauric acid. A satisfactory yield of To a three-necked 5-liter flask equipped as above benzoyl chloride and cyclohexoyl chloride is obtained. was added crotonic acid, 25 grams (2.5 mols); EXAMPLE 6 O benzotrichloride, 495 grams (2.525 mols); SnCl4, 5.15 grams (0.0195 mol); and benzene, 612.5 grams. The The procedure of Example 1 is repeated substituting flask was heated under reflux for 2.5 hours at 89 to 94 an equivalent molar amount of 3-methyl C. Following this, the material was fractionated benzotrichloride for the benzotrichloride. A satisfacto through a 13-inch Vigreux column at atmospheric pres ry yield of 3-methyl benzoyl chloride and lauroyl 5 sure, at a vapor temperature of 80 to 132C., to give chloride is obtained. 825 grams of distillate. A pot residue of 408 grams EXAMPLE 7 remained. The distillate was a mixture of benzene, crotonyl chloride and SnCl4. The pot residue contained Thiodipropionic acid, 2.5 mols, is substituted for the some tarry material, benzoyl chloride and the excess 5 mols of lauric acid in the procedure of Example 1. A 20 unreacted benzotrichloride. satisfactory yield of thiodipropionyl chloride and There was substantially complete conversion of the benzoyl chloride is obtained. crotonic acid and benzotrichloride to the benzoyl EXAMPLE 8 chloride and crotonyl chloride, respectively. There was 25 substantially no chlorination of the unsaturated car Adipic acid, 2.5 mols, is substituted for lauric acid in bon-carbon link in the crotonyl group. the procedure of Example 1. A satisfactory yield of The same reaction carried out in the absence of adipoyl chloride and benzoyl chloride is obtained. benzene resulted in the formation of a substantial quan EXAMPLE 9 tity of 3-chlorobutyryl chloride, about 20 mol percent 30 of the product, which was distilled off together with In the process of Example 1, SnCl is substituted for crotonyl chloride. SnCl, and the process is otherwise carried out in the A similar reaction was carried out utilizing a dry same manner. Substantially the same yields of the lau nitrogen gas sparge. To a 500 ml. three-necked glass royl chloride and benzoyl chloride are obtained. flask was added crotonic acid, 43 grams (0.5 mol); 35 EXAMPLE 10 benzotrichloride, 97.75 grams (0.5 mol); and SnCl4, 1.3 grams (0.005 mol). The reaction product was The following materials are charged to a three heated to 85 C. and held there for 1.5 hours during necked 5-liter flask equipped as above: trimelitican which time dry nitrogen was passed through the reac hydride (TMA), 960 grams (5 mols); benzotrichloride, 40 tion vessel above the reaction mixture. The product 990 grams (5.05 mols); and SnCl4, 10.3 grams (0.0398 contained 11.75 percent chlorinated crotonyl chloride mol). and 88.5 percent crotonyl chloride. This shows a sig The pot contents were heated to 105 C., at which nificant reduction in the amount of hydrochlorination point a heavy evolution of hydrogen chloride com of the unsaturated chain linkage. menced and continued for 30 minutes. The tempera 45 The benzene acting as a diluent and as a carrier to ture was then raised to 125 C. and held there for 1.5 aid in the removal of the HCl as it is formed substan hours. tially eliminates the problem of hydrochlorination of The reaction mixture was then vacuum distilled. The the unsaturated carbon-to-carbon linkages, whereas cut going over at 78 to 83 C. at 10 mm pressure com the use of a nitrogen gas sparge to remove the hydrogen prised 742.1 grams and consisted of 705 grams of 50 benzoyl chloride, the unreacted excess of 10 grams chloride is not quite as effective, as seen above. benzotrichloride, 10 grams SnCl4 and 17.1 grams 4 EXAMPLE 12 acid chloride of trimelitic acid. A second fraction was collected at a vapor temperature of 180 to 184 C. at The reaction flask was charged with the following 10 mm. pressure, and comprised 846.5 grams of the 4 55 reactants: 790 grams pelargonic acid (5.0 mols), 990 acid chloride of trimelitic acid. The residue of 147 grams benzotrichloride (5.05 mols), and 10.3 grams grams consisted mainly of the 4-acid chloride plus SnCl4 (0.0398 mol). The reaction mixture was heated some tarry residue. to 100°C. for 1.5 hours. The reactants were completely The yield of benzoyl chloride was 100 percent, and converted, i.e., the reaction product (96 percent the yield of the 4-acid chloride was approximately 85 60 weight yield of mixed acid chlorides) was analyzed by percent. The yield of the 4-acid chloride would have gas-liquid chromatography, and was found to contain been higher except for the problem of separating out 65 percent benzoyl chloride and 35 percent pelar the remaining 4-acid chloride from the residue without gonoyl chloride, which was a satisfactorily high yield of degrading the material. the desired reaction product. In this Example, the Accordingly, this test shows that in a polycarboxylic 65 products had extremely close boiling points, and acid where two of the carboxyl groups come from a separation by distillation would have been difficult to cyclic anhydride, the third group can be selectively and achieve. 3,691,217 11 12 EXAMPLE 13 matography and comparison with known samples In a 500 ml, three-necked flask was placed fumaric showed that 2 percent or less of the benzotrichloride acid, 58 grams (0.5 mol); benzotrichloride, 195.5 and methacrylic acid starting materials remained, that grams (1.0 mol); and SnCl4, 2.6 grams (0.01 mol). The benzoyl chloride and methacryloyl chloride had been mixture was heated to 130° C. and held at that tem formed in high yield, and that a trace (2 percent or perature for 1.75 hours. Gas-liquid chromatography less) of 3-chloroisobutyryl chloride hydrochlorination showed that there remained approximately 10 percent product was the only extraneous compound formed. unreacted benzotrichloride. EXAMPLE 1.9 EXAMPLE 14 O The procedure of Example 18 was repeated with The procedure for Example 1 is repeated, substitut acrylic acid (36 g, 0.5 mole) in place of methacrylic ing an equivalent molar amount of myristic acid in acid. Analysis of the treated reaction mixture as above place of the lauric acid. A satisfactory yield of benzoyl showed consumption of the starting materials to 2 per 15 cent or less, formation of benzoylchloride and acryloyl chloride and myristoyl chloride is obtained. chloride containing approximately 20 percent 3 EXAMPLE 1.5 chloropropionyl chloride in good yield, and no extrane ous compounds. The procedure of Example 1 is repeated, substituting an equivalent molar amount of 2,4-dichlor EXAMPLE 20 benzotrichloride for the benzotrichloride and pelar In each experiment 99 g benzotrichloride (0.505 gonic acid for the lauric acid. A satisfactory yield of mole), 100 glauric acid (0.5 mole), and metal chloride 2,4-dichlorobenzoyl chloride and pelargonic chloride is as shown were heated together for one and one-half obtained and separated by fractional distillation under hours at 100° C. and analyzed by GLC. Where benzoyl WaCUU. 25 chloride and lauroyl chloride were found present, they EXAMPLE 16 were isolated by distillation under reduced pressure. Results are tabulated: Benzylidene chloride 80.5 g (0.5 mole) propionic acid 37 g (0.5 mole) and stannic chloride 1.3 g (0.005 Benzoyl Lauroyl 30 Run Metal chloride chlorideComments mole) were stirred and heated for one and one-half chloride yield, moles yield, moles hours at 100° C. in a reaction flask equipped as in Ex % of % of ample 1. Analysis of the reaction mixture by gas chro theoretical theoretical matography and comparison with known samples showed that 2 percent or less of the benzylidene a One O O Starting material 35 found unchanged chloride and propionic acid starting materials Ex. SnCl 0.48 (96) 0.45 (90) - remained, that benzaldehyde and propionyl chloride 20 1.30 g. b HgCl, O O Starting material had been formed in high yield, and that no extraneous 1.35 g, found unchanged compounds had been formed. c MgCl, O O a 40 0.5 g. EXAMPLE 1 7 d AlCl O O 0.7 g. Tris (2-dichloromethylphenyl) phosphate, melting e MoCl O O 0.9 g. point 75 C., was obtained from the chlorination of tri f CHSnCl 0. l l (22) 0.03 (6) - o-tolylphosphate at 165°-170° C. for 16 hours. 1.4g. 45 g BuSnCl O O Starting material The phosphate (5.72 g., 0.01 mole), propionic acid 1.5 g. found unchanged (2.22 g., 0.03 mole) and stannic chloride (0.078 g., h BuSnCl O O AV V& 0.0003 mole) were heated one and one-half hours at 1.6 g. i SbCl. 0.31 (62) 0.075 (15) Large distilla 100° C. Hydrogen chloride was evolved. Vacuum was 1.2g. tion residue applied at 100° C. to remove volatile materials includ j SbCl, 0.245 (49) 0.035 (7) L 50 105 g. ing propionyl chloride and unreacted propionic acid. k FeCl 0.455 (91) 0.225 (45) The residue of tris (salicylaldehyde) phosphate was a 0.8 g. brown oily liquid; it was characterized by conversion to l ZnCl 0.23 (46) O 37 37 the semicarbazone melting point 130-134° C. by 0.7 g. warming with semicarbazide hydrochloride in aqueous 55 methanol. The semicarbazone was free of chlorine; its Under conditions where SnCl4 works very well, only infrared spectrum exhibited characteristic absorption the antimony chlorides and zinc and ferric chloride peaks of P=O and P-O-aromatic groups and was con show any catalytic activity, and these chlorides at the sistent with the assigned structure. same time cause considerable degradation of the 60 desired fatty acid chloride so that their utilization is im EXAMPLE 1.8 practical. Benzotrichloride (99 g. 0.5 mole), methacrylic acid In a further experiment with zinc chloride, the (43 g, 0.5 mole), stannic chloride (1.3 g, 0.005 mole) catalyst quantity for a run as shown was increased to and methylhydroquinone polymerization inhibitor 6.8 g and the heating period extended to 21 hours at (0.004 g) were stirred and heated one and one-half 65 130°C. These conditions resulted in 66 percent yield of hours at 100° C. in a reaction flask equipped as in Ex benzoyl chloride and zero yield of lauroyl chloride, ample 1. Analysis of the reaction mixture by gas chro along with a large distillation residue. 3,691,217 13 14 EXAMPLE 2. said carboxylic acid groups to form acid chloride The following experiments were carried out to in groups substantially to the exclusion of anhydride vestigate whether the catalytic properties found with groups, and recovering from the reaction mixture the tin chlorides in bringing about the interaction of acid chloride of the organic carboxylic acid and the benzopolychloromethane with a carboxylic acid to give 5 acid chloride O aldehyde of the high yields of oxoarylmethane and carboxylic acid benzopolychloromethane. chloride could be duplicated with organic chlorine 2. The process of claim 1 wherein the organic car compounds other than benzo polychloromethanes. boxylic acid has the formula R(COOM) in wherein R In each experiment, 37 g propionic acid (0.5 mole), is selected from hydrocarbon groups and hydrocarbon 1.3 g tin tetrachloride (0.005 mole) and the quantities O groups bearing one or more inert substituents and hav of chlorine compound shown were heated at 100° C. ing from one to about 50 carbon atoms, and n is a for one and one-half hours and analyzed by gas chro number from one to about six, and M is hydrogen or a matography. Only the peaks characteristic of the start salt-forming cation, there being no more than one car ing materials were observed. boxylic acid group -COOM per R carbon atom. 15 3. The process of claim 2 wherein R is selected from the group consisting of aliphatic, aromatic, and Run Chlorine compound Comments cycloaliphatic hydrocarbon groups. benzyl chloride 64 g 4. The process of claim 3 wherein R is a saturated DDT 179 g DDT recovered by aliphatic hydrocarbon group. crystallization s hexachlorocyclohexane 147 g CHClarecovered by 5. The process of claim 1 wherein the reaction is car crystallization ried out under reflux in an inert solvent to remove hydrogen chloride. 6. The process of claim 1 carried out at a tempera Each of these chlorine compounds is lacking a 25 ture of from about 80 to about 140°C. characteristic feature of the benzopolychloromethanes. 7. The process of claim 1 wherein the tin chloride is Benzyl chloride has one chlorine instead of two or in an amount within the range from about 0.1 to about three; DDT is a benzopolychlorolethane, with the 10 percent by weight of the reaction mixture. chlorinated side chain carbon separated from the aro 8. The process of claim 1 wherein the reaction mix matic ring by an intervening carbon atom; hexachloro 30 ture is sparged with a nitrogen gas stream to remove cyclohexane is lacking the aromatic ring. hydrogen chloride. The acid chlorides and benzaldehydes that are ob 9. The process of claim 1 wherein the tained by the process of the invention are known com benzopolychlormethane is a benzotrichloride. pounds, and have known utilities, and accordingly form 10. The process of claim 1 wherein the no part of the instant invention, which is concerned 35 benzopolychlormethane is a benzylidene chloride. with a process for their preparation. 11. The process of claim 1 wherein the organic car Acid chlorides are especially useful as intermediates boxylic acid is a polycarboxylic acid having at least two for the formation of other commercially valuable com carboxylic acid groups reactive to form a cyclic an pounds. For example, the acid chlorides can be used hydride, and the remaining carboxylic acid groups are for the preparation of the corresponding organic perox 40 selectively reacted with the benzpolychloromethane to ides by reaction with hydrogen peroxide or a metal form acid chloride groups while substantially excluding peroxide, e.g., barium peroxide or sodiumperoxide: cyclic anhydride formation by the reaction of the car boxylic acid groups reactive to form a cyclic anhydride. 2RCO C -- Iso-R goor - 2Cl 12. The process of claim 1 wherein the organic car 45 boxylic acid is a monocarboxylic acid. O O 13. The process of claim 1 wherein the organic car See Organic Peroxides, E.G.E.Hawkins, D.Van Nos boxyacid is a dicarboxylic acid. trand Company, Inc. (Princeton, N.J., 1961). 14. The process of claim 1 wherein the reaction is Acid chlorides are also used to react with aminoacids carried out under substantially anhydrous conditions. such as glycine, sarcosine, N-methyl taurine, and beta 50 15. The process of claim 1 wherein the organic car alanine in the synthesis of surface-active agents. boxylic acid is in the form of the alkali metal, or al Benzaldehydes are also useful intermediates, and kaline earth metal salt. components of perfumes and aromatic oils and es 16. The process of claim 1 wherein the SeCeS. benzopolychloromethane and organic carboxylic acid Having regard to the foregoing disclosure, the fol 55 both have the same hydrocarbon groups, to which the lowing is claimed as the inventive and patentable em polychloromethane and the carboxylic acid groups are bodiments thereof. attached. 1. A process for the preparation of aromatic acid 17. The process of claim 1 wherein the reaction chlorides and aldehydes and acyl chlorides, comprising products are separated from the reaction mixture by reacting an organic carboxylic acid having carboxylic fractional distillation. acid groups that form non-cyclic acid anhydride, acid 18. The process of claim 1 wherein the tin chloride is halide, O aldehyde groups with a. SnCl2. benzopolychloromethane having two or three chlorine 19. The process of claim 1 wherein the tin chloride is atoms in the methane group in the presence of a stannic 65 SnCl or stannous chloride at a temperature within the range 20. The process of claim 1 wherein the from about 40 to about 170° C, limiting the propor benzopolychloromethane has the formula: tions of benzopolychloromethane to limit reaction to 3,691,217 15 16 H. 23. The process of claim 20 wherein Aris R' (6-m) - in2 5 {DY-Ki > where R' is selected from hydrogen and halogen, alkox------y, hydrocarbon and hydrocarbon bearing one or more 10 wherein Y is a linking nucleus Selected from inert substituents selected from halogen, oxyether, thioether, sulfoxyl, carboxyl, ester or nitro, having from -C- one to about 50 carbon atoms, Ar includes at least one aromatic six-numbered carboxylic ring, m is a number from 1 to 6, and n is zero to one. 15 21. The process of claim 20 wherein Aris O O O-; -C-; - S-;-O l O-; s () ) 20 22. The process of claim 20 wherein Aris { )-( ) in being one or two. ck k ck sk xk 25

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