DK146908B - PROCEDURE FOR THE PREPARATION OF STERICALLY HINED BIS OR POLYPHENOLS - Google Patents

Description

(19) DENMARK VJf./

ff | dg PRESENTATION SCRIPTURE (s) 146908 B

DIRECTORATE OF

THE PATENT AND TRADEMARKET SYSTEM

(21) Patent Application no .: 2603/77 (51) Int.CI.3: C 07 C 39/16 (22) Filing date: 13 | un 1977 C 07 C 37/20 (41) Alm. available: 15 Dec 1977 (44) Submitted: 06 Sep 1984 (86) International Application No: - (30) Priority: 14] un 1976 SU 2372253 (71) Applicant: 'NAUCHNO-ISSLEDOVATELSKY INSTITUT REZINOVYKHI LATEXNYKH IZDELY; Moscow, SU, • STERLITAMAXKY OPYTNO-PROMYSHLENNY NEFTEKHIMICHESKY ZAVOD; Bashklrskaya ASSR, SU.

(72) Inventor; Evgeny Lvovich * Stysktn; SU, Yakov Abramovich * Gurvlch; SU, Slmona Tevlevna ‘Kumok; SU, Olga Fedorovna 'Starikova; SU, Grigory losKovich 'Rutman; SU, Jury Ivanovlch 'Michurov; SU,

Vladimir Avgustovich ‘Yanshevsky; SU, Vladimir Konstantlnovich ‘Gusev; SU, Alexandr Grigorievlch • Liakumovlch; SU.

(74) Plenipotentiary: International Patent Bureau_ (54) Process for the preparation of sterically hindered bis or polyphenols

The present invention relates to a process for the preparation of rigidly inhibited bis or polyphenols which are useful as effective, non-staining, non-toxic and slightly volatile stabilizers for rubber products, vulcanizers, resins and other organic products.

These stabilizers can be exemplified by such a known compound as 2,2'-methylene-bis- (4-methyl-6-tert-butylphenol) prepared under the trade names, Antioxidant 2246 '* and KAO-5.

There are various methods known in the art for preparing sterically hindered bisphenols or polyphenols. For example, a process is used in the preparation of 2,2'-methylene-bis- (4-methyl-6-tert-butylphenol), in which the desired product is prepared by alkylation of 4-methylphenol with isobutyl - The mixture in the presence of a catalyst followed by separation and condensation of the resulting 2-tert.butyl-4-methylphenol with formaldehyde.

2 146908

The condensation is carried out in the presence of acidic catalysts such as sulfuric acid. The process is carried out in an aqueous emulsion containing a surfactant and an organic solvent at a temperature in the range of 75 ° to 90 ° C, cf. U.S. Patent No. 245,127 and U.S. Patent No. 2,675,366.

This known method has the disadvantage of a complicated technology for the process.

The process is carried out in two steps and a large amount of wastewater 3 is formed (about 30 m per tonne of product) which is contaminated with surfactants and organic solvents. Furthermore, as a starting product is used in the process p-cresol, which is difficult to obtain.

Since ρ-cresol is a critical product, another method has been developed for the preparation of 2,2'-methylene-bis- (4-methyl-6-tert.butylphenol) from 2,6-ditert.butyl-4- methylphenol based on the preparation of the latter fairly readily from cheap and readily available phenol. The process is based on dealkylation of 2,6-ditert.hutyl-4-methylphenol followed by separation and condensation of the resulting 2-tert.buty: fc-4- methylphenol with formaldehyde, see SU Patent No. 403,663.

One of the major drawbacks of this process also lies in the formation of a large amount of acidic wastewater containing surfactants and organic solvents. Purification of such wastewater on a commercial scale is rather complicated and 'economically inefficient. '"

Also known in the art is a process for the preparation of 2,2 * methylene bis (4-methyl-6-tert.butylphenol) which has certain advantages over the above processes as it allows the formation of wastewater to be eliminated. . According to this known process, the desired product is recovered from 2,6-ditert.butyl-4-methylphenol in two steps, namely dealkylation of 2,6-ditert.butyl-4-methylphenol followed by separation and condensation of the resulting 2 -tert.butyl-4-methylphenol with an acetal in the presence of an acidic catalyst at a temperature in the range of from 30 ° to 140 ° G, cf. BE Patent No. 836,745 and DD Patent 121,777.

This known process as well as those described above are two-step processes and require the separation, in pure form, of 2-lert.butyl-4-methylphenol having a strong, unpleasant odor, high toxicity and volatility. Furthermore, a complicated process technology is required for carrying out all the known methods mentioned above.

Furthermore, the known methods described above only allow bisphenols to be prepared. In the field of polyphenols, complex multistage methods are known in the art for their preparation. For example, according to US Patent No. 3,297,575 polyphenols are prepared by reacting para-alkylphenols with free ortho positions with chloromethyl derivatives of 2,6-dialkylphenols according to the following reaction scheme: 3 146908

OH OH

r ^ Vl <C !, 3> 2C - CH2 _ f ^> |

yj "2S04 O

C (CH3) 3

OH OH OH

Jv «» 3> 3C \ JL / C (CH3) 3 (CH3) 3C I, C (CB3) 3 ΓΛΛ1 W9C -CH? ^ Γ / ^ ντ hci, ch o y <0 ^ ·· - - y - * o CH2C1

OH OH

X. «Wv 1 /« »3> 3 p 'W - = * - C (CH3 ^ 3 CH2C1 y <cH3> 3 C (OH) OH / ^ S \

J \ JC / CH2 — O — 0B

* H0 3 (oh3.3 cfcH,) - I3.3 C (CH3) 3

The present invention aims to eliminate the above-mentioned drawbacks associated with the methods known in the art.

4 146908

According to the present invention, by appropriate choice of reactants and conditions for their mutual reaction, a simple one-step process for producing sterically hindered bis and polyphenols is provided which ensures high yield of the desired product.

The process of the present invention for the preparation of sterically hindered his? or polyphenols of the general formula R "R-C ™ R" '(R 1 where R' is hydrogen or C 1 -C 4 alkyl, R "and R 1 M are the same or different and are a group

OH

'ψ R2 or

OH OH

R1 R1 or R1 ^

H0 - ^ C ^> - 012--0H

R

wherein R is tertiary C 1 -C 6 alkyl and R 1 and R 2 are the same or different and are C 1 -C 8 alkyl, C 9 -C 8 cycloalkyl or C 1 -C 2 aralkyl, are characterized by sterically hindered 2,4,6-trialkylphenols of the general formula:

OH

"R2 or 5 146908

Off OH

τφ - ", '- ~ i · E1 E1 or H0 - (Ό) -CH2- (O / - Εΐ" VZ "R1 where R1 and R2 are as defined above are reacted with acetals of the general formula: - O - CH - O - R, R 'where R 1 is C 1 -C 4 alkyl and R 1 is as defined above, or with aldehydes of the general formula R 1 -CHO where R 1 is as above defined, or cyclic or linear oligomers thereof, in acidic medium at temperatures of 60 ° to 200 ° C in the presence of an acidic catalyst.

Acidic catalysts are preferably used as acids such as sulfuric acid, orthophosphoric acid, polyphosphoric acid, perchloric acid, toluene sulfonic acid, naphthalene sulfonic acid and cation exchangers in H + form, or Lewis acids such as zinc chloride, aluminum chloride, ferric chloride and boron trifluoride. These catalysts can be easily separated from the desired product and provide a yield, based on the reacted starting 2,4,6-trialkylphenol, of at least 78.7% and preferably at least 95% of the theoretical yield.

As acetal, commonly available and readily useful compounds are preferably used.

Certain acetals are waste products from other syntheses. In particular, methylal is a waste product from the synthesis of isoprene katusjuk. Among acetals, methylal, ethylal or dipentylformal are particularly preferred, but other acetals such as dimethylacetal, diethylacetal and diisopropylacetal can be used.

As aldehyde, acetaldehyde, propionaldehyde, butyraldehyde, isobutyraldehyde, valeraldehyde or isovaleraldehyde are preferably used as these are readily available and readily usable reagents. It is also possible to use formaldehyde and other aldehydes.

6 146908

As cyclic aldehyde oligomers, in acidic medium, e.g. trioxane, paraldehyde or 2,4,6-tri-isohutyl-1,3,5-trioxane as these products are more stable in storage and easier to use compared to the monomeric aldehydes.

Among cyclic oligomers, trioxane is particularly preferred, as the most valuable antioxidants are the sterically hindered bis or polyphenols having methylene bridges between the aromatic rings.

The preferred linear oligomeric aldehydes belong to paraformaldehyde, as it, like trioxane, ensures the incorporation of methylene bridges between the aromatic rings, thereby contributing to the formation of the most valuable methylene bisphenols or methylene polyphenols.

The process of the invention is carried out as follows: In a four-neck reactor equipped with a stirrer, thermometer, cooler and heating bath, a sterically hindered 2,4,6-trialkylphenol such as 2,6-ditert.butyl-4-methyl-phenol, an acid, is introduced. catalyst, such as sulfuric acid after a H + form cat zinc or zinc chloride, and the mixture is heated to a predetermined temperature with stirring. While maintaining this temperature, an reactor which is still stirred for 0.5-2 hours introduces an acetal such as methylal or an aldehyde such as acetaldehyde or a linear aldehyde oligomer in acidic medium such as paraformaldehyde.

The process temperature is maintained in the range of 60 ° to 200 ° C. Upon completion of the reaction, the catalyst is separated and the desired product is isolated by conventional techniques such as crystallization.

The yield of the desired products is as high as 78.7 to 99.1% of theory, calculated for the reacted sterically hindered 2,4,6-trialkylphenol, mostly above 95%. For the most effective stabilizer, ie. 2,2'-methylene bis- (4-methyl-6-tert.butylphenol), the yield is as high as 97.8-99.1%. The process of the invention ensures the preparation of high quality compounds. Thus, 2,2'-methylene bis (4-methyl-6-tert.butylphenol) prepared by the process of the present invention shows a melting point of 131-131.5 ° C (according to literature data, the melting point of the compound is 131-132 ° C).

The method according to the invention has certain advantages compared to the methods known in the art. The selected reactants and their reaction conditions ensure the preparation of the desired bisphenols or polyphenols from sterically hindered 2,4,6-trialkylphenols in a single step, therefore the process technology is substantially simplified and the sanitary and hygienic conditions at work improved. as no pure 4-methyl-2- tert.butylphenol is developed during the process which exhibits high toxicity, strong and unpleasant odor and high volatility. The process produces high quality products which do not require further crystallization. Bisphenols or polyphenols can be recovered from monophenols by the process of the invention by selecting suitable reaction conditions. The unreacted starting products are recycled in the process. The tertiary definitions derived from the reaction are used in the preparation of the sterically hindered 2,4,6-trialkylphenols used as starting material. The process of the invention completely eliminates the formation of wastewater and atmospheric pollutants.

The process according to the invention is further described by the following examples.

Example 1 Into a reactor equipped with a stirrer, thermometer and heating bath was introduced 220 g (1 gram mol) of 2,6-di-tert-butyl-4-methylphenol and 2.2 g of concentrated sulfuric acid and the mixture was heated to a temperature of 120 ° G. While maintaining the temperature at 120 ° C, 94 g (1.24 grams) of methylal were introduced into the reactor over 1.5 hours. After completion of the reaction, the catalyst was separated and volatiles were distilled off in vacuo to give 143.0 g of 2,2-methylene bisi - (- 4 · methyl-6-tert-butylphenol), corresponding to 97.8 % of theory, calculated on the converted 2,6-ditert.butyl-4-methylphenol (conversion rate of the latter 86.0%).

After a single recrystallization, the resulting product had m.p. 131-131.5 ° C (according to the literature mp 131-132 ° C).

Unreacted 2,6-ditert.butyl-4-methylphenol and methylal were recycled in the process.

Example 2 In a reactor similar to that described in Example 1, 220 g (1 gram) of 2,6-ditert.butyl-4-methylphenol and 2.2 g of concentrated sulfuric acid were introduced, and at a temperature of 120 ° C 76 g ( 1.0 gram mol) of methylal in the reactor over 1 hour. The reaction mixture was treated in the manner described in Example 1 to give 112.9 g of 2,2'-methylene-bis (4-methyl-6-tert.butylphenol) to give 99.17 2,6-ditert.butyl-4-methylphenol (the conversion of the latter was 67.0%). Unreacted methylal and 2,6-ditert.butyl-4-methylphenol were recycled in the process.

Example 3 In a reactor as described in Example 1, 220 g (1.0 gram) of 2,6-ditert.butyl-4-methylphenol and 2.2 g of sulfuric acid and 44 g (1 gram) of acetate were added. aldehyde was introduced into the reactor over 1 hour at a temperature of 125 ° C.

After completion of the reaction, the reaction mixture was treated by the same procedure as described in Example 1 to give 124.6 gl, 1-bis- (5-methyl-3-tert-butyl-2-hydroxyphenyl) ethane, which was 96.4% of the theoretical calculated for the converted 2,6-ditert.butyl-4-methylphenol (the conversion of the latter was 73%).

After a single recrystallization, the resulting product had m.p. 104 ° to 104.5 ° C (according to the literature the product has mp 104.5 ° G).

Unreacted 2,6-ditert.butyl-4-methylphenol and acetaldehyde were recycled in the process.

Example 4 In the reactor described in Example 1, 212 g (0.5 gram mole) of 4,4'-methylene bis- (2,6-ditert.butylphenol) and 8.4 g of zinc chloride and 10 g (0.111 gram mole) were introduced. trioxane was added to the mixture over 30 minutes at a temperature of 200 ° C. Upon completion of the reaction, the catalyst was separated and volatiles distilled in vacuo to give 193.7 g of 2,2-methylene bis- [4- (3,5-di-tert-butyl-4-hydroxybenzyl) -6 tert.butylphenol] in the form of a resin of molecular weight 736 (the theoretical molecular weight of the condensation product is 748).

Example 5 In the reactor described in Example 1, 170 g (0.5 gram mol) of 2.2, methylene bis- (4-methyl-6-tert.butylphenol) and 34 g of a cation exchange resin in H + form ( sulfonated copolymer of styrene with divinylbenzene), and at a temperature of 160 ° C, 8.2 g (0.26 grams) paraform (calculated for the 95% product) was added to the reaction mixture over 1 hour. Upon completion of the reaction, the catalyst was separated and volatiles were distilled off in vacuo to give 141.9 g of a resin containing 46.1% by weight of the condensation product, i.e. 2,2, -methylene bis- [4-methyl-6- (3-tert-butyl-5-methyl-2-hydroxybenzyl) phenol], and 53.9% by weight of the starting product. The resulting resin could be used as an antioxidant.

Example 6 In the reactor described in Example 1, 282 g (1 gram mole) of 2,4,6-tert-butylphenol and 9 g of concentrated sulfuric acid were introduced and 110 g (1.17 gram mole) of dipentyl formal was introduced into the reactor during 2 hours at a temperature of 60 ° C. Upon completion of the reaction, the catalyst was separated and volatile products were distilled off in vacuo to give 120.7 g of the desired product, i.e. 2,2'-methylene-bis- (4,6-ditert.butylphenol), which accounted for 98.2¾ of the theoretical calculated for the converted 2,4,6-ditert.butylphenol (the conversion of the latter was 53%).

After a single recrystallization, the resulting product had m.p. 141-9 U6908 142 ° C.

Unreacted 2,4,6-triturated butylphenol and dipentylformal were recycled in the process.

Example 7 In the reactor described in Example 1, 155 g (0.5 gram mole) of 2,6-di-tert-butyl-4-a-methylbenzylphenol and 3 {, 2 g para-toluenesulfonic acid, and 21.9 g (0.255 gram mole) were introduced. ) isovaleraldehyde was added at a temperature of 150 ° C over 1.5 hours. Upon completion of the reaction, the catalyst was separated and volatiles were distilled off in vacuo to give 120.9 g of 1,1-bis- (6-tert-butyl-4-a-methyl-benzylphenol) isopentane, corresponding to 95.8 % of theory calculated for the converted 2,6-ditert.butyl-4-α-methylbenzylphenol (the conversion of the latter was 88%).

Example 8 In the reactor described in Example 1, 330 g (1.5 gram) of 2,6-di-tert-butyl-4-methylphenol and 6.5 g of concentrated sulfuric acid were added and 152 g (2 gram of methylene) methylal was added over of 2 hours at a temperature of 150 ° C. Upon completion of the reaction, the catalyst was separated and volatiles were distilled off in vacuo to give 200.3 g of the desired product, i.e. 2,6-di- (5-methyl-3-tert.butyl-2-hydroxybenzyl) paracresol, which accounted for 87.1% of theory, calculated for the converted 2,6-ditert.butyl-4- methylphenol (the conversion of the latter was 100%).

island

After recrystallization, the product thus obtained had m.p. 163-163.5 ° C.

Example 9 In the reactor described in Example 1, 220 g (1.0 gram) of 2,6-di-tert-butyl-4-methylphenol and 11 g of ortho-phosphoric acid were introduced and 66 g (1.5 gram) of acetaldehyde were added. added at a temperature of 150 ° C over 1 hour. After completion of the reaction, the catalyst was separated and volatiles were distilled off in vacuo to give 210 g of a mixture of 1,1-H 5 (5-methylhSR tert JbutyE-2-hydroxyphenyl) ethane and 2,6-di- ( 5-methyl-3-tert-butyl-2-hydroxy "olrmethylbenzyl) para-cresol. The resulting mixture can be used as an antioxidant without any breakdown. The conversion of 2,6-ditert.butyl-4-methylphenol was 99%.

r

Example 10 In the reactor described in Example 1, 123 g (0.5 gram mol) of 2-tert.butyl-6-cyclohexyl-4-methylphenol and -2.2 g of concentrated sulfuric acid were introduced and the mixture was heated at a temperature of 120 ° G. . Then at this temperature to the reactor 47 g (1.12 gram mol) of methylal were added over 1.5 hours. After the reaction was complete, the catalyst was separated and volatiles were distilled off in vacuo to give 163.1 g of 2,2'-methylene-bis- (4-methyl-6-cyclohexyl-phenol) to give 99.1¾ of the theoretical calculated for the reacted 2-tert-butyl-6-cyclohexyl-4-methylphenol (the conversion of the latter was 84%).

island

After recrystallization, the resulting product had m.p. 117-117.5 C.

Unreacted 2-tert-butyl-6-cyclohexyl-4-methylphenol and methylal were recycled in the process.

Example 11 In the reactor described in Example 1, 159 g (0.5 gram) of 2,6-di-tert-butyl-4-tert.-octylphenol and 2 g of concentrated sulfuric acid were introduced and 36 g (0.5 gram) of butyraldehyde was added. to the reactor at a temperature of 125 ° C over 1 hour. Upon completion of the reaction, the catalyst was separated and volatiles were distilled off in vacuo to give 103.3 g of the desired product, i. 1,1-H- (3-tert-butyl-5-tert.octyl-2 «-hydroxyphenyl) -butane, which represented 95.3% of theory, calculated for the converted 2,6-ditert.-butyl-4 -tert.octylphenol (the conversion of the latter was 75.0%).

Unreacted 2,6-ditert.butyl-4-tert.octylphenol and butyraldehyde were recycled in the process.

Example 12 In the reactor described in Example 1, 234 g (1 gram mole) of 2-tert-octyl-4,6-xylenol and 2.4 g of concentrated sulfuric acid were introduced and 76 g (1 gram mole) of methylal was added at a temperature of 100 ° C over 1 hour. The reaction mixture was treated by the procedure of the previous Example 11 to give 63.5 g of the desired product, i.e. 2,2'-methylene-bis- (4,6-dimethylphenol), representing 81.1% of theoretical yield, calculated for the converted 2-tert-octyl-4,6-xylenol (the conversion of the latter was 61 , 2%).

Unreacted 2-tert-octyl-4,6-xylenol and methylal were recycled in the process.

Example 13 In the reactor described in Example 1, 58.5 g (0.25 gram) of 2,6-di-tert-butyl-4-ethylphenol and 1 g of concentrated sulfuric acid were introduced and 19 g (0.25 gram) of methylal was added. to the reactor at a temperature of 130 ° G over 30 minutes. The reaction mixture was treated to give 26.2 g of 2,21-methylene-bis- (4-ethyl-6-tert.butyl-phenol), corresponding to 98.97. of the theoretical yield calculated for the converted 2,6-ditert.butyl-4-ethylphenol (the conversion of the latter was 57.5%).

After a single recrystallization, a product having m.p.

Claims (2)

124.5-125.0 ° C. Unreacted 2,6-ditertbutyl-4-ethylphenol and methylal were recycled in the process * Example 14 In the reactor described in Example 1 141.0 g (0.5 gram mol) of 2-tert.butyl-4 were introduced. methyl 6-cumylphenol and 1.5 g of concentrated sulfuric acid, and 52 g (0.5 gram mol) of ethylal were added to the mixture at a temperature of 130 ° C over 1 hour. Upon completion of the reaction, the catalyst was separated and unreacted 2-tert.-butyl-4-methyl-6-cumylphenol and ethylal were distilled off in vacuo to yield 62.5 g of the desired product, i.e. 2,2-methylene-bis- (4-methyl-6-cumylphenol), which accounted for 78.7% of the theoretical yield, calculated for reacted 2-tert-butyl-4-methyl-6-cumylphenol (the conversion of the latter was 68.5%). Non-traded products were recycled in the process. Example 15 In the reactor described in Example 1, 70.5 g (0.25 gram) of 2-tert.hexyl-4-methyl-6-benzylphenol and 20 g of a cation exchange resin in H + form (sulfonated copolymer of styrene with divinylbenzene) and 17.4 g (0.3 gram mol) of propiondehyde were added to the reactor at a temperature of 145 ° G over 30 minutes. Upon completion of the reaction, the catalyst was separated and volatiles were distilled off in vacuo to give 31.4 g, 1-bisr (5-methyl-3d3enzyt-2-hydroxy-phenyl) propane, which was 91.1% of the theoretical yield calculated for reacted 2-tert.hexyl-4-methyl-6-benzylphenol (conversion of the latter was 63.2%). Unreacted 2-tert.hexyl-4-methyl-6-benzylphenol and propionaldehyde were recycled in the process. Process for the preparation of sterically hindered bis or polyphenols of the general formula: R "- C - R, MIR 'where R' is hydrogen or C 1 -C 4 alkyl, R" and R "'are the same or different and are a group OH * 2 12 148908 or OH OH τ6τ “τάτ Ri Ri or R1 _ R1 ho- (Q) -ch2- \ Cy OH where R is tertiary C 1 -C 6 alkyl and R 1 and R 2 are the same or different and are C --C C-C, alkyl, Cg-Cg cycloalkyl or C--C ^ aralkyl, characterized in that sterically hindered 2,4,6-trialkylphenols of the general formula: OH 'Tér' · R2 or OH OH 'φτ R 1 or R 1 or R 2> - ch 2 - (C 2 - ° h R 1 * 1 where R, R 2 and R 2 are as defined above are reacted with acetals of the general formula: