PROCESS FOR PREPARING CARBONATOALKYL acrylates and methacrylates

United States Patent Ofice, 2,979,514 » Patented Apr. 11, 1961 2,979,514 PROCESS FOR PREPARING CARBONATOALKYL ACRYLATES AND M'.ETHACRYLATE;§ Joseph L. ‘O’Brien and Ellington M. Beavers, Elhns Park, Pa., assignors to Rohm & Haas Company, Philadel- phia, Pa., a corporation of Delaware No Drawing. Filed July 16, 1957, Ser. No. 672,128 "1 ‘Claim. (Cl. 260—340.2)‘ This invention relates to carbonatoalkyl acrylates and methacrylates, processes for preparing same, and poly- mer and copolymer products containing one or more of them. More particularly, the new compounds above referred to have the general formula 0 t n . CH2=(|3—C—-O—(CHz)n—CH——CH: R \ /J) L C 3 wherein R is a hydrogen atom or a methyl group and n is an integer having a value from one to four, inclu- sive. Examples of such compounds are as follows: 2,3-carbonatopropyl acrylate 2,3-carbonatopropyl methacrylate 3,4-carbonatobutyl acrylate 3,4-carbonatobutyl methacrylate 4,5-carbonatopentyl acrylate 4,5-carbonatopentyl methacrylate 5,6-carbonatohexyl acrylate 5,6-carbonatohexyl methacrylate They are prepared by reacting the corresponding di- hydroxyalkyl acrylates or methacrylates with phosgene or a lower alkyl ester of chloroformic acid, such as ethyl chloroformate in the presence of a hydrogen chloride acceptor such as sodium carbonate, pyridine, triethyl-’ amine, or a basic anion exchange resin, as illustrated below: (a) CH2=C—C 0gOH«_»CHCH2OH+G 0 Clg+2C5H5N-——> I H: OH CH-2=C———C O;»CH2CH——-CH2+2C5H5N.HC1 (IJH3 (g \c H O / b) . CH2=?-C 02CH2CH2CH2CHCHn0H-I-CIC O2C2H5+C5H5N—"-* CH3 H CHFC—C O2CH2CH20H2CH-—-CH2+CzH50H-I-C5H5N.HC1 «EH. \ ‘:3 O / 5 10 15 20 25," 30 35 40 45 50 55 60 2 In an alternative procedure,’ the appropriate carbonate- substituted alcohol is reacted with acrylyl chloride or methacrylyl chloride or a lower alkyl ester of acrylic or methacrylic acid under suitable conditions, as illustrated in the following examples. (6) CH2=C—C O2CHa-I-H0 CH2CH:-CH2"'—* H’ \ / C 3 CH2=C—-C 02CHzCH-—-CH2-I-CHaOH er. .3 \C/ II 0 (d) ' CH2==CH—C 0 Gl+HO CH2CH——CHg+C5H5N——> \C/ 3 C5H5N._HC1+CH2-”-‘CH_—'C02CH2CH—--CH2 » t . 4, cl) . _\C/ . ('5 7 Thedihydroxyalkyl acrylates and methacry_lates.used as starting materials in accordance with this invention, (a) and (b) above, are prepared by the selective hy- drolysis of the corresponding isopropylidene derivatives in accordance with the disclosure of an application, en- titled “Process for Preparing Dihydroxyalkyl Acrylates and Methacrylates,” Serial No. 672,129, filed. of even date herewith, and now abandoned. . — Carbonato-substituted alcohols suitable for use in the alternative procedure‘ described above, (c) and (d), in- clude the commercially available 2,3-carbonatopropano1- 1, which is called “glycerine carbonate” (Jefferson Chemi- cal Co.), and similar carbonato-substituted alcohols. The following working examples further illustrate spe- cific embodiments of this invention. ’ ’ A. Preparation of 2,3-carbonatopropyl methacrylate In a 2—liter 3-necked flask equipped with a’ stirrer, thermometer,-addition funnel and 20" packed column was placed 236 g. (Zmoles) of ‘glycerine carbonate, 600 ’ g. (6 moles) of methyl methacrylate, 8.0 g. of, hydro- quinone and 400 ml. of dry benzene. Thefractionating column was fitted with an automatic distillation head and thermoregulator set for _a—maxirnum distillation tempera- ture of 65° C. Heat was appliedto the stirred reaction mixture and a solution of,0.5 g. of sodium in 10 ml. of methanol was added over a period of 10 hours. ~ During this period, a total of 190 ml. (99% of the theoretical amount) of the benzene-methanol azeotrope (B.P. 58° C.) was collected at the top of the column. The reaction mixture was allowed to cool to _room temperature, filtered and washed with water. The organic layer was dried with anhydrous MgSO4, filtered and stripped under reduced pressure. The residue. was distilled in three portions in the presence of the poly‘- merization inhibitor N,N’-di-2-(1,4-napththoquinonyl)-i 2,979,514 3 p-phenylenediamine to give a total of 261 g. (70% yield) of 2,3-carbonatopropyl methacrylate, B.P. 112-132" C./ 0.06 mm. Analysis.—Found: Saponification No. 624 (phenol- phthalein indicator). Calculated for C3H1oO5 (2 equiv.) : Saponification No. 603. Redistillation of a portion of the above product gave a -pure sample of 2,3-carbonatopropyl methacrylate, B.P. 113—127° C./0.10 mm., nD25, 1.4629. Analysis.——Found: C, 52.5%; H, 6.0%; saponification No. 595 (phenolphthalein indicator); saponification No. 298 (methyl red indicator). Calculated for C3H10O5: C, 51.6%; H, 5.4%; saponification No. (2 equivalents), 603; saponification No. (1 equivalent), 302. , The infrared spectrum of the above compound was found to contain a number of bands characteristic both of the methacrylate ester group and the cyclic carbonate group, thus providing further confirmation of the proposed structure. B. Preparation of 2,3-carbonatopropyl methacrylate To a solution of 118 g. (1 mole) of glycerine carbonate, 79 g. (1 mole) of pyridine, and 1.0 g. of hydroquinone in 400 ml. of chloroform, there was added 104.5 g. (1 mole) of methacrylyl chloride over a period of one hour with stirring. During the addition and subsequently for two hours, the temperature of the reaction mixture was held -at 0—10° C. by vigorous cooling. After it had warmed to room temperature, the reaction mixture was washed successively with ice-cold 5% aqueous sodium hydroxide, dilute aqueous HCl and water. The chloro- form solution was dried with anhydrous MgS04, filtered and stripped under reduced pressure in the presence of 1.0 g. of hydroquinone and 2.0 g. of N,N’—di-2-(1,4- naphthoquinonyl)-p-phenylenediamine. The residue was distilled at reduced pressure. The product which col- lected at 118-128‘ C./0.2 mm. amounted to 66.0 g. (35.5% yield) and was identified at 2,3-carbonatopropyl methacrylate, nD25 1.4640. C. Preparation of 2,3—carbonatopropyl methacrylate To a solution of 80 g. (0.50 mole) of 2,3-dihydroxy- propyl methacrylate, 1.5 g. of hydroquinone and 250 ml. of pyridine, there was added a solution of 49.5 g. (0.50 mole) of phosgene in 75 ml. of dry toluene over a period of one—half hour. During the addition the temperature of the reaction mixture was held at 15-25 ° C. by vigorous cooling. The mixture was stirred for an additional 4 hours at room temperature. The crystalline precipitate of pyridine hydrochloride was removed by filtration, and the filtrate stripped under reduced pressure. The residue was distilled under reduced pressure in the presence of N,N’-di-2-( 1,4-naphthoquinonyl) —p-phenylenediamine. The product which collected at 122-127 ° C./0.15 mm. amounted to 36.0 g. (39% yield) and was identified as 2,3-carbonatopropyl methacrylate. D. Preparation of 4,5-carbonatopentyl methacrylate To a solution of 75 g. (0.40 mole) of 4,5-dihydroxy- pentylmethacrylate and 32 g. (0.405 mole) of pyridine, there was added 43.5 g. (0.40 mole) of ethyl chloro- formate over a period of one-half hour. During the addition the temperature of the reaction mixture was held at 35—40° C. by moderate cooling. After stirring for an additional hour at room temperature, the mixture was filtered to remove the crystalline precipitate of pyridine hydrochloride. 10 15 20 25 30 35 40 50 6‘! U1 60 65 The filtrate was charged to a fresh reaction flask and - stirred overnight at room temperature with 1.0 g. of dry powdered sodium methoxide. Anhydrous benzene (200 ml.) was then added -and the mixture was washed suc- cessively with dilute aqueous HCI, ice-cold 5% aqueous sodium hydroxide and brine. The organic layer was dried with anhydrous MgSO4, filtered and stripped under reduced pressure in the presence of 1.0 g. of N.N’-di—2- 70 75 4 (1,4-naphthoquinonyl)-p-phenylenediamine. The residue was treated with 0.05 g. of hydroquinone and distilled under reduced pressure. The product which collected at 165—168° C./0.7 mm. amounted to 14.8 g. (17% yield) and was identified as 4,5-carbonatopentyl meth- acrylate, nD25 1.4543. E. Preparation of 5,6-carbonatohexyl methacrylate To a mixture of 20.2 g. (0.10 mole) of 5,6—dihydroxy- hexyl methacrylate, 50 ml. of anhydrous toluene and 60 g. of a strongly basic anion exchange resin of the quater- nary ammonium hydroxide type, there was added a solu- tion of 9.9 g. (0.10 mole) of phosgene in 25 ml. of dry toluene over a period of, one-half hour. During the addition, the temperature was allowed to rise to 45° C. The reaction mixture was stirred and heated at 45° C. for an additional 4 hours. The mixture was then cooled and the anion exchange resin removed by filtration. The fil- trate Was stripped under reduced pressure in the presence of 0.2 g. of N,N’-di-2—(1,4-naphthoquinonyl)-p—phenyl- enediamine. The residue was distilled under reduced pressure. The product which collected at 184—188° C./ 2.4 mm. amounted to 11.5 g. (50% yield) and was identified as 5,6-carbonatohexyl methacrylate. F. Preparation of 2,3—carbonatopropyl acrylate To a solution of 118 g. (1 mole) of glycerine carbon- ate, 79 g. (1 mole) of pyridine and 1.0 g. of hydro- quinone in 350 ml. of benzene, there was added 90.5 g. (1 mole) of acrylyl chloride over a period of one hour with stirring. During the addition, the temperature of the reaction mixture was held at 5-10° C. by vigorous cool- ing. The mixture was allowed to warm to room tempera- ture and was stirred for an additional -hour. The crystalline precipitate of pyridine hydrochloride was removed by filtration and the filtrate washed suc- cessively with dilute aqueous HCI, ice-cold 5% aqueous sodium hydroxide and water. The benzene solution was dried with anhydrous MgSO4, filtered and stripped un- der reduced pressure in the presence of 0.5 g. of hydro- quinone. The residue was a clear, yellow oil which amounted to 138 'g. (80% yield) and was identified as 2,3-canbonatropropyl acrylate. G. Polymerization of 2,3-carbonatropropyl methacrylate in Sheet form A mixture of 120 g. of 2,3-carbonatopropyl met—hac- rylate, 0.03 g. of benzoyl peroxide catalyst and 0.06 g. each of a common peak suppressant and mold release agent was heated briefly with moderate stirring and poured into a small plate glass mold. The mold was placed in a hot air oven and held at 60° C. until stifien- ing of the mix was observed. A conventional polymeri- zation cycle (60—1-10° C.) was then begun. On com- pletion of the cycle, the casting separated easily from the mold, with no evidence of let-go or adhesion. The sheet was clear and colorless, with excellent surface quality. Specimen -bars were cut from this plastic sheet and heat-treated at 180° C. for 11/2 hours, followed by a slow cooling or annealing. The resultant material showed no evidence of thermal decomposition and had a heat distortion temperature of 130° C. it was highly resistant to the common organic solvents, including such solvents -as, chloroform, dimethyl formamide and propyl- ene canbonate. V H. Copolymerization of 2,3-carbonatopropyl methacry- late with methyl methacrylate A mixture of 20 g. of 2,3-carbonatopropyl methacry- late, 80 g. of methyl methacrylate, 0.02 g. of benzoyl peroxide catalyst and 0.06 g. each of a common peak suppressa.ut and mold release agent was polymerized in sheet form in the manner described -in Example G. The resultant material was clear and colorless and had 2,979,514 5 a heat distortion temperature of 107° C. It was mod- erately resistant to the common organic solvents. I. Copolymerization of 2,3-carbonatopropyl methacrylate with an unsaturated polyester resin A clear blend of 60 g. of a polyester derived from maleic anhydride and dipropylene glycol and 40 g. of 2,3-carbonatopropyl methacrylate was obtained by stir- ing the components at 80° C. in a glass vial. To the re- sultant solution was added 1.5 g. -of ter-t.—buty1 perben- zoate and the mixture heated for one hour each at 80° C C., 90° C., 100° C., and 120° C. After cooling slowly to room temperature, the contents of the vial were re- moved and found to consist of a— slightly hazy’ plastic having a Barcol hardness value of 50. The polyester resin composition had excellent solvent resistance, show- ing no evidence of attack by toluene, acetone or di- rnethylformamide. ’ We claim: « . . A process for prepar-ing a compound of the formula 0 ll CH2=C-—C—O-(CH2)..-CH——-CH: 1'. .3 cl \G/ 8 wherein R is -a member of the class consisting of a by- 5 10. 15 20 .25 6 drogen atom and a methyl group and n is an integer hav- ing a value of one to four, inclusive, which comprises reacting, while removing heat generated by the reaction and in the presence of a basic hydrogen chloride accep- tor, a compound of the -formula 0 I . CH2=$—-(J/‘—O—(CHz) n-—CIE[—CHaOH R H wherein R and n are as above indicated, with a com- K pound from the group consisting of phosgene and an alkyl ester of chloroformic acid wherein the alkyl group contains one to four carbon atoms. 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