3,190,882 United States Patent Office Paiented June 22, 1965 1. 2 tolualdehyde, etc., is well known in the art and hence is 3,190,882 not described in further detail. AM EDOMETHYLATION OF OLEFENS In any of the foregoing permutations, the terminal ends Willian E. Sciaeffer, Poinona, Calif., assignor to Union of the R4 and R8 radicals can be joined together to form (ii Company of California, Los Angeles, Calif., a cor a cyclic amide or imide. Suitable examples include N poration of California methylol formamide, N-methylol acetamide, N-methylol No Prawiag. Fied Aug. 14, 1961, Ser. No. 131,09 propionamide, N-methylol - N - methyl formamide, N 3 Caians. (C. 260-268) methyol-N-methyl acetamide, N-methylol diacetamide, This invention relates to the amidomethylation of N-methylol succinimide, bis-methylol urea, N-methylol olefinic compounds and to the product obtained thereby. 10 2,5-diketo-piperaZene, and the like... The preferred class This invention is based on my discovery that olefinic of N-methylolamides is represented by the formula: compounds can readily be amidomethylated in high yields and purity with various acidic catalysts. Although it has O been known that aromatics can be amidomethylated with R&NHCHOH - acid catalysts, it heretofore was not expected that the wherein R4 is hydrogen or a lower alkyl radical having 1 amidomethylation reaction could be used to produce to about 6 carbons, and said N-methylolamide is derived amidomethylated olefin derivatives. from the reaction of formaldehyde with the correspond The resulting amidomethylated compounds are useful ing carboxylic acid amide. intermediates for the production of a variety of valuable The aimidomethylation step is conducted in the presence products. They may, for example, be hydrolyzed to form 20 of a strong acid catalyst, which is non-oxidizing and does alkenyl or alkanol amines having two functional or re not react with the substrate materials. I have found the active sites useful as intermediates for polymers, ion ex following catalysts suitable: Sulfuric acid of a strength change resins, etc. Reduction of the alkenyl inter between about 50 and 100 volume percent, anhydrous mediates presents a method of preparing their carbinyl hydrofluoric acid, trifluoroacetic acid, aryl and alkyl sul amines. fonic acids having between one and about 8 carbons, such Olefinic compounds which are readily amidomethylated as, benzene sulfonic acid, toluene sulfonic acid, methane in accordance with my invention are, in general, com sulfonic acid, ethane sulfonic acid, propane sulfonic acid, pounds free of interfering functional groups which cor butane sulfonic acid, etc, respond to the general structure: The aqueous sulfuric acid, anhydrous hydrofluoric acid 30 and trifluoroacetic acid catalysts are employed in liquid phase and suitably serve as the reaction media. A sol wherein R1, R2 and Rs are selected from the class con vent, however, is employed with the sulfonic acid catalysts sisting of hydrogen, alkyl, nitroalkyl, carboxyalkyl and and optically the solvent can also be used with the sul mixtures thereof; and the total of carbon atoms of said furic, hydrofluoric and trifluoroacetic acid catalysts. This olefin are between about 2 and 25. solvent can suitably be any inert, i.e., non-ionized com Examples of suitable olefinic compounds are the foll pound such as dioxane, diethyl ether, dibutyl ether, lowing: ethylene, propylene, butene, isobutene, nitro methylbutyl ketone, sulfur dioxide, etc. - - pentene, 2,3-dimethyl butene, hexene, heptene, 2-ethyl-1- The aforedescribed catalyst and optional solvents are pentene, 3-methyl-2-pentene, ... diisobutene, decene, 4 employed to obtain alkenyl annides in accordance with butyl-2-hexene, 6-initro-1-undecene, octadecene, docosene, 40 the preceding equation. etc.; unsaturated fatty acids such as acrylic acid, crotonic I have also discovered that the amidomethylation re acid, tiglic acid, myristoleic acid, hypogaeic acid, oleic action can be directed to production of alkyl ester amides acid, abeitic acid, etc. . . . . by the addition of an alkanoic acid to the system. The The amidomethylation reaction whereby the afore reaction is then expressed as follows: described olefinic compounds are substituted proceeds as O O follows: + O RéN(R) C (Ro) HOH. H.C (R)=C(R) R8 - Ri O --> O , RdN(Roc (R) HoH + Ho (R)=c(R) R. hum-9 O 50 R&NO (R) CHCR) CH(R)&(R)- - or, R, The N-methylolamide reactant of the preceding equa wherein R1 through Rs are as previously described and tion is prepared in a conventional manner by reacting a O. carboxylic acid amide with an aldehyde as follows: Réon O O , represents the alkanoic acid and is selected from the foll R.N.R.) H + c (R) Ho - R&N (Rec(R) HOH lowing: carboxylic acids...such as acetic acid, propionic in general, any carboxylic acid amide free of inter acid, butyric acid, isovaleric acid, valeric acid, caproic fering functional groups can be employed wherein R acid, enanthic acid, capyrlic acid, perlargonic acid, capric may be a primary: or secondary methylolamide such as 60 acid, etc. another -NRCHOH, hydrogen, alkyl group such as Only relatively mild reaction conditions are needed methyl, ethyl, propyl, isopropy, butyl isobutyl, hexyl, for the amidomethylation reaction which is conducted in dodecyl, etc.; and R5 may be hydrogen; an alkyl such as the liquid phase at temperatures between about 0° to methyl, ethyl, propyl, isopropyl, butyl, isobutyl, hexyl, about 200° C. Temperatures between about 10 and 120° dodecyl; or an alkylol radical such as formyl, acetyl and C. are preferred, especially when using the more active the like. - - - . catalysts such as hydrogen fluoride, trifluoroacetic acid, As used herein, the term N-methylolamide. is generic and methane sulfonic acid. Slightly higher temperatures to N-methylolamides wherein Rs is hydrogen, and to N can be used for the less active catalyst, e.g., 50° to 200° C. methylolamides having an alkyl or aryl Substituent in In general pressures between about 1 and 20 atmos the methylol group. The preparation of these N-methylol 70 pheres are employed; preferably the pressure employed amides from a carboxylic acid amide and an aldehyde is the minimum necessary to maintain the reactants in such as formaldehyde, acetaldehyde, propanol, butanol, liquid phase at the reaction temperatures; however, the 3,190,882 3 4. pressure is not critical to the process and higher pressures be separaated therefrom by conventional means, e.g., can be used if desired. filtration, decantation, etc. Under the aforementioned conditions of temperature Bases can also be used to hydrolyze the amide products and catalyst, the reaction will ordinarily be completed in directly to the amine. In general, the amidomethylated about 10 minutes to 2 hours. This reaction time, how olefin product can be added to an aqueous solution of an ever, is not universal for all olefins. In the manner ap alkali, e.g., sodium, potassium or ammonium hydroxide parent to those skilled in the art, the amidomethylation of about 5 to 50 weight percent strength and the admix rate of any particular olefin can be determined by periodic ture heated to between about 100 and 250 C. under withdrawal of samples for routine analysis such as boiling sufficient pressure to maintain a liquid phase for about 5 point, refractive index, rate of disappearance of a reactant 0. minutes to 3 hours. The amine can readily be separated by means of other physical means such as infra-red spectra, from the aqueous phase by filtration, decantation, extrac nuclear magnetic resonance, etc. tion, etc. The aqueous residue is thereafter treated to In general, it is preferred to employ a slight excess of recover carboxylic acids, RCOOH and RCOOH, for re the olefinic reactant, as any excess of this reactant is easier use in the process. When aqueous ammonia is employed to remove than excess N-methylolamide reactant. To ef 15 as the hydrolysis media, the aqueous residue is distilled fect the reaction, the desired reactants are simply agitated under reduced pressure, 10 to 600 millimeters of mercury, together until the reaction is complete. In a preferred to recover the carboxylic acid amide which is then reacted modification, the N-methylolamide is added gradually to with formaldehyde to form the N-methylolamide reactant the olefin-catalyst mixture, in order to avoid undesired for the process. The lower molecular weight amides side reactions. This modification is particularly de 20 which are stable at their atmospheric boiling point, acet sirable when higher temperatures are employed, which amide, propionamide, butyramide, etc., can of course be sometimes tend to cause two molecules of the N-methylol distilled at atmospheric pressure if desired. When alkalis amide to react with each other, eliminating water and are used to catalyze the amide hydrolysis, the aqueous forming a diamido ether or a methylene bis-amide. residue can be acidified to yield the carboxylic acids The amidomethylated product can be recovered by 25 which can be separated by extraction for reuse. several methods. When using volatile acid catalysts such In a preferred embodiment, the alkanoic acid used as as hydrogen fluoride and trifluoroacetic acid, the product a condensing agent in the formation of the previously de is readily separated by distillation. With non-volatile acids scribed alkyl ester amides corresponds to the carboxylic such as the sulfonic acids, separation is best accomplished acid portion of the N-methylolamide reactant, i.e., R. by quenching the reaction mixture in water and filtering 30 and R4 are the same radicals. This embodiment elimi off the aqueous solution of catalyst which can be concen nates the need to purify two carboxylic acids from the trated for reuse. Where a solvent is employed in the re aqueous residue of the acid or base catalyzed hydrolysis. action zone it is preferably removed by distillation prior When carboxylic acids of dissimilar R and R radicals to quenching. are used, it is within the scope of my invention to con While the alkanol amide and alkylene amide reaction duct the alkyl ester amide hydrolysis in two steps. In products are useful for a variety of chemical intermediates, the first step, mild conditions are used, e.g., acid or base their greatest value is an intermediate in the formation of catalysts at temperatures between about 25° and 150° C. primary amines. As previously mentioned, the amine is so as to hydrolyze the ester portion and yield the R acid readily prepared by simple hydrolysis of the amide or salt. This product is then separated from the aqueous formed. 40 system by suitable methods, e.g., extraction. Thereafter The conditions for hydrolysis of amides to amines are the hydrolysis temperature can be increased and/or the well known and are applicable to the amidomethylated strength of the acid or base catalyst increased so as to hy products of my invention. In general, any strong acid drolyze the amide to the amine or ammonium salt. The or base catalyzes the hydrolysis. The acid hydrolysis of amine is thereafter recovered in the appropriate manner the alkylene amide product yields the alkenyl ammonium 45 previously described. salt as follows: My invention will now be described by the following O examples which are intended for illustration only and are RCN (R) CEI(R) C (R)=C(R) Rs -- IX -- HO --> not to be construed as unduly limiting of the invention: O Example I 50 To a 200 milliliter flask fitted with a reflux condenser acid hydrolysis of the alkyl ester amide product yields the is added 90 milliliters of acetic acid, 10 grams of p-toluene alkanol ammonium salt as follows: Sulfonic acid, 25 milliliters of 1-hexene and 17.8 grams of O N-methylolacetamide. The mixture is heated to reflux 55 temperature (about 115° C.) and then 5 milliliters of O o&R, acetic anhydride is added. After a six-hour reflux period, RéNCR) CHCR) CH(R)' (R) R, -- 2EX -- 2EO --> the mixture is cooled and poured into an excess of cold O O OH dilute potassium hydroxide solution (6 N). After ex --- R. OH -- R. OH + XNH2(R) CH(R6) (R1) C(R) R3 tracting the aqueous mixture twice with 75 milliliter por 60 tions of ethyl ether, the combined extracts are evaporated wherein the R groups are as previously described and HX under vacuum to yield 11 grams of liquid residue. In represents a strong mineral acid such as hydrochloric, frared spectroscopy and elemental analysis indicate the Sulfuric, etc., having a strength between about 5 and 35 product to be N-acetoxyheptyl-acetamide. weight percent. The hydrolysis temperature is between When the experiment is repeated with methanesulfonic about 100 and 250 C. and sufficient pressure is used to 65 acid in acetic acid and 80 C. for one hour a 58 percent maintain a liquid phase. yield of N-acetoxyheptyl-acetamide is obtained. Similar The hydrolysis product can be recovered in any suitable results are obtained when octene is amidomethylated to manner, e.g., the system can be evaporated to remove N-acetoxynonyl-acetamide. water and the non-volatile portion extracted with an or ganic solvent to recover the RCOOH carboxylic acid and 70 Example 2 RCOOH condensing agent for reuse in the process. The To a 250 milliliter flask equipped with a reflux con purified alkanol or alkylene ammonium salt can then be denser, stirrer and thermometer is added 16.8 grams of added to an aqueous solution of an alkali, e.g., sodium 1-hexene and 50 milliliters of trifluoroacetic acid. The potassium, ammonium hydroxides, etc., to form the free mixture is stirred and 17.8 grams of N-methylolacetamide amine which is insoluble in the aqueous system and can 75 is added dropwise. During addition, the temperature 3,190,882 5 6 slowly rises. After addition of the N-methylolacetamide claim: is completed, the flask is heated to 80-85 C. for one 1. A method for preparing unsaturated amides which hour. Thereafter unreacted 1-hexene and excess trifluoro comprises contacting a monoolefin having the following acetic acid are removed by evaporation under vacuum. formula: The residue is poured into dilute potassium hydroxide and twice extracted with 100 milliliter portions of ethyl wherein R1,R2 and R3 are selected from the class con ether. The extracts are combined and evaporated to sisting of hydrogen, alkyl, nitroalkyl and carboxyalkyl yield 22 grams of N-heptenylacetamide corresponding to and the total carbon atoms of said monoolefin are between a 71 percent yield. 2 and about 25 with an N-methylolamide at a reaction When the experiment is repeated with 70 volume per 0. temperature between about 0 and about 200° C. in the cent sulfuric acid at 30° C. for 30 minutes, substantially presence of an acidic condensing catalyst selected from the same results are obtained. the class consisting of anhydrous hydrogen fluoride, tri When hexene is amidomethylated with a catalyst com fluoroacetic acid, sulfuric acid having a strength between prising 10 grams hydrogen fluoride in 70 grams of sul about 50 and 100 volume percent, alkyl and aryl sulfonic fur dioxide in a pressure bomb for one hour and 25 C., 5 acids having 1 to about 8 carbon atoms, and mixtures a 22 percent yield of N-heptenylacetamide is obtained. thereof; and thereafter recovering said unsaturated amide Example 3 product. 2. A method as defined in claim 1 wherein said N To a 250 milliliter flask equipped with a stirrer, ther methylolamide is N-methylolformamide. mometer, reflux condenser and inlet tube are added 60 20 3. A method as defined in claim 1 wherein said N milliliters of trifluoroacetic acid. Propylene is passed methylolamide is N-methylolacetamide. through the inlet tube at about one liter per minute while 4. A method as defined in claim 1 wherein said acidic 17.8 grams of N-methylolacetamide are slowly added condensation catalyst is anhydrous hydrogen fluoride. over a ten minute period. After addition, the flask is 5. A method as defined in claim 1 wherein said acidic heated to 70° C. and maintained at this temperature for 25 condensation catalyst is trifluoroacetic acid. 30 minutes. Excess trifluoroacetic acid is evaporated 6. A method as defined in claim 1 wherein said acidic from the flask under vacuum and the residue is added to condensation catalyst is methane sulfonic acid employed dilute potassium hydroxide. The resultant solution is in a liquid reaction medium comprising a solvent inert to extracted three times with 75 milliliter portions of ethyl said olefin under said reaction conditions. ether, the extracts combined and evaporated by yield 13 30 7. A method as defined in claim 1 wherein said acidic grams of N-butenylacetamide. condensation catalyst is sulfuric acid having a strength between about 60 and 80 volume percent. Example 4 8. A method for the preparation of an amido ester Oleic acid is amidomethylated by adding 28.2 grams of 35 which comprises contacting a monoolefin having the fol oleic acid to 30 milliliters of trifluoroacetic acid in a 250 lowing formula: milliliter flask. To the stirred mixture is slowly added 9.0 HC(R)=C(R2)R. grams of N-methylolacetamide and the resultant mixture wherein R, R2 and R3 are selected from the class con thereafter heated to 50° C. for one hour. After one hour sisting of hydrogen, alkyl, nitroalkyl and carboxyalkyl the flask contents are poured into ice water. The product 40 and the total carbon atoms of said monoolefin are between is purified and found to be an amidomethylated oleic acid 2 and about 25 with an N-methololamide and an alkyl in about a 95 percent yield. Substantially the same yields carboxylic acid at a reaction temperature between about can be obtained when 7.5 grams of N-methylolformamide 0 and about 200° C. in the presence of an acidic con or 10.3 grams of N-methylol-N-methyl acetamide are em densing catalyst selected from the class consisting of ployed in lieu of N-methylolacetamide anhydrous hydrogen fluoride, trifluoroacetic acid, sulfuric 45 acid having a strength between about 50 and 100 volume Example 5 percent alkyl and arylsulfonic acids, and mixtures thereof; and thereafter recovering said alkyl ester amide. Diisobutylene is amidomethylated by adding 22.4 grams 9. A method defined by claim 8 wherein said alkanoic of the hydrocarbon to 80 milliliters of trifluoroacetic acid acid is acetic acid and said N-methylolamide is N-methyl in a 250 milliliter flask. To the stirred mixture is added 50 olacetamide. 18 grams of N-methylolacetamide and the reactants are 10. A method as defined in claim 8 wherein said N maintained at about 60° C. for one hour and then poured methylolamide is N-methylolformamide. onto crushed ice. The mixture is neutralized with potas 1. A method as defined in claim 8 wherein said acidic sium hydroxide to yield a two-phase system. The organic condensation catalyst is anhydrous hydrogen fluoride. phase is extracted with benzene and the extract concen 55 12. A method as defined in claim 8 wherein said acidic trated to obtain about an 84 percent yield of N-nonenyl condensation catalyst is trifluoroacetic acid. acetamide. Substantially the same yields are obtained 13. A method as defined in claim 9 wherein said acidic when 23.6 grams of bis-methylol urea, 23.0 grams of N condensation catalyst is methane sulfonic acid. methylol succinimide or 29.0 grams of N-methylol 2,5- 14. A method as defined in claim 8 wherein said acidic diketo-piperazine are used in lieu of the N-methylol 60 condensation catalyst is sulfuric acid having a strength acetamide reactant, the respective products being N-non between about 60 and 80 volume percent. enyl-N'-methylol urea and N-nonenyl 2,5-diketo piper 5. The method of preparing an amine which com azine. E. contacting a monoolefin having the following for Example 6 la 65 To illustrate the hydrolysis of the amidomethylated olefin products, 10 grams of N-heptenylacetamide are wherein R1, R2 and R3 are selected from the class con added to 150 milliliters of concentrated (28 percent) am sisting of hydrogen, alkyl, nitroalkyl and carboxyalkyl monium hydroxide solution in a 300 milliliter pressure and the total carbon atoms of said monoolefin are be bomb. The bomb is heated to 175° C. for 90 minutes, 70 tween 2 and about 25 with an N-methololamide at a then cooled and the contents removed and extracted with reaction temperature between about 0° and about 200° ethyl ether to recover primary heptenyl amine. The aque C. in the presence of an acidic condensing catalyst select ous residue containing ammonium acetate is heated to ed from the class consisting of anhydrous hydrogen fluo 180° C. under reduced pressure to distill over and recover ride, trifiuoroacetic acid, sulfuric acid having a strength acetamide for reuse in the process. 75 between about 50 and 100 volume percent, alkyl and aryl 3,190,882 7 8 sulfonic acids having between about 1 and about 8 carbon i3. The method defined by claim 17 wherein the atoms, and mixtures thereof; thereafter separating an amine product is separated from said aqueous phase, said amidomethylated olefin product from said catalyst and aqueous phase is thereafter heated under reduced pres contacting said amidomethylated olefin with water at a Sure to distill overhead a carboxylic acid amide and said temperature between about 100 and 250° C. to hydrolyze 5 carboxylic acid amide is reacted with an aldehyde to re said product and form said amine. generate said N-methylolamide. 16. The method defined by claim 15 wherein said amine is an alkanolamine and said amidomethylation is No references cited. conducted in the presence of an alkanoic acid. 17. The method defined by claim 15 wherein said hy O IRVING MARCUS, Primary Examiner. droylsis is conducted at a temperature between about 100 DUVAL T. McCUTCHEN, Examiner. and 250 C. in an aqueous phase containing ammonium hydroxide.