Other

Yakov Abramovich Gurvich

Jury Ivanovich Michurov

Alexandr G Liakumovich

Grigory I Rutman

Vladimir Avgustovich Yanshevsky

Simona T Kumok

Evgeny L Styskin

Igor Jurievich Logutov

Alexandr Afroimovich Grinberg

Vladimir A Yanshevsky

Olga Fedorovna Starikova

Valerian Mikhailovich Sobolev

Boris Izrailevich Pantukh

Izrail M Belgorodsky

Nina Vasilievna Zakharova

Alexandr Grigorievich Liakumovich

Jury I Michurov

Felix Borisovich Gershanov

Rufina Alexandrovna Filippova

Grigory Iosifich Rutman

Alexei S Polenov

Almira Mudarisovna Nafikova

Engel R Adigamov

Galina G Latysheva

Anna I Rybak

Sofya Alexandrovna Egoricheva

Rufina A Filipova

Igor J Logutov

Sergei Gerasimovich Vyborov

Vladimir K Gusev

A method for preparing sterically hindered bis- or polyphenols of the formula: ##STR1## wherein R' is hydrogen, a C.sub.1 -C.sub.4 alkyl; R' and R'' the same or different and are each: ##STR2## wherein R is a tertiary C.sub.4 -C.sub.8 alkyl, R.sub.1 and R.sub.2 are the same or different and represent a C.sub.1 -C.sub.8 alkyl or a C.sub.6 -C.sub.8 cycloalkyl, or a C.sub.7 -C.sub.9 aralkyl, which comprises reacting the starting sterically hindered 2,4,6-trialkylphenols of the formula: ##STR3## wherein A is a C.sub.1 -C.sub.8 alkyl or a C.sub.6 -C.sub.8 cycloalkyl or a C.sub.7 -C.sub.9 aralkyl or a 3,5-dialkyl-2-hydroxybenzyl of the formula: ##STR4## B is a C.sub.1 -C.sub.8 alkyl, or a C.sub.6 -C.sub.8 cycloalkyl, or a C.sub.7 -C.sub.9 aralkyl, or a 3,5-dialkyl-4-hydroxybenzyl of the formula: ##STR5## wherein R.sub.1 and R are as identified above, with acetals, aldehydes or donors of C.sub.1 -C.sub.5 aldehydes in an acidic medium at a temperature within the range of from 60.degree. to 200.degree. C. in the presence of an acidic catalyst, followed by isolation of the desired product. The method according to the present invention makes it possible to prepare sterically hindered bis- or polyphenols in a single stage, whereby the process technology is substantially simplified as compared to those of the prior art. The method of the present invention precludes formation of waste water and atmospheric pollutants. The method ensures preparation of the desired products possessing high quality in high yield without any additional crystallization.

Method for preparing sterically hindered bis- or polyphenols

A method for the production of 2,4,6-tri(3,5-ditertiary butyl-4-hydroxybenzyl)mesitylene which resides in treating a mesitylene solution in chloroalkane simultaneously with sulfuric acid used as a catalyst and a solution of 2,6-ditertiary butyl-4-methoxymethylphenol or bis-3,5-ditertiary butyl-4-hydroxybenzyl ether in chloroalkane at a temperature of -20.degree. to +20.degree. C. This results in a reaction mixture consisting of an acid phase and an organic phase including the target product. The phases are separated. The organic phase is subjected to neutralization by the treatment thereof with gaseous ammonia used as an alkaline agent. The precipitate of ammonium sulfate is separated and chloroalkane is removed from the remaining solution. The proposed method makes it possible to obtain the target product with a yield of 88 to 90% and a melting temperature of 239.degree. to 239.5.degree. C. The method prevents the formation of effluents, and the amount of phenol wastes is considerably reduced.

Method for the production of 2,4,6-tri(3,5-ditertiary

Method of removing aluminum-containing catalyst from phenol alkylation products comprises treating phenol alkylation products with water at a temperature of 165.degree.-250.degree. C., with water being in molar excess to aluminum in a range of 3-20. The resulting residue of meta-aluminate is easily separated by filtration. The present invention allows eliminating constant control of aluminum content in alkylation products, easily removing the catalyst therefrom and eliminating the loss of phenol alkylation products.

Method of removing aluminum-containing catalyst from phenol alkylation

A method for preparing 2,6-ditert.butylphenol which comprises alkylation of phenol in the presence of monotert.-butylphenol and a catalyst, viz. aluminium dissolved in phenol with gradually lowering the process temperature from 120.degree. to 50.degree. C and reducing the concentration of isobutylene in the mixture of isomeric butenes from 80 to 1.5 mol.%, followed by isolation of the desired product. The method according to the present invention makes it possible to achieve a high degree of conversion of isobutylene without impairing quality of the desired product. The amount of by-products formed in the process is 2-3 times as less as in the prior art methods.

Method for preparing 2,6-ditert.butylphenol

A method of producing 2,2'-methylenebis(4,6-dialkylphenols) residing in that 2,4-dialkylphenols interact with acetals in the presence of an acid catalyst at a temperature from 30.degree. C to 140.degree. C with the formation of a reaction mixture containing the desired product and with subsequent separation of the desired product from said mixture, the starting reagents being taken in amounts of 1 mole of 2,4-dialkylphenol per 1-10 moles of acetal. The method is technologically simple and accomplished without the formation of waste water.

Method of producing 2,2 '-methylenebis(4,6-dialkylphenols)

A method of producing 2,6-dialkyl- and 2,6-diaralkyl-substituted derivatives of p-cresol of the general formula ##SPC1## Wherein R signifies an alkyl group having from 4 to 12 carbon atoms or ##SPC2## Comprising subjecting phenol to alkylation with olefines having from 4 to 12 carbon atoms or with styrene at a temperature of 50.degree.-150.degree.C in the presence of a catalyst, namely, aluminum, taken in an amount of 0.1-5 wt.% of phenol. 2,6-Dialkyl phenol or 2,6-diaralkyl phenol resulting after from the alkylation is treated with a mixture of formaldehyde and dimethylamine or with a product of their interaction having the formula ##EQU1## at a temperature of 20.degree.-100.degree.C with subsequent catalytic hydrogenolysis of N,N-dimethyl(3,5-dialkyl-4-hydroxybenzyl)/amine or N,N-dimethyl(3,5-diaralkyl-4-hydroxybenzyl/amine at a temperature of 80.degree.-200.degree.C., molar ratio of hydrogen to the product being treated of 1-5:1 and space velocity of 0.1-2 hour.sup..sup.-1. The products produced by said method feature a high degree of purity, and they can be employed as effective inhibitors of thermooxidation degradation of polymers and hydrocarbon fuels, and also as intermediates for producing p-cresol, and 2-alkyl- and 2-aralkyl-substituted derivatives of p-cresol.

Method of producing 2,6-dialkyl- and 2,6-diaralkyl-substituted

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Moscow, Russia

Yakov Abramovich Gurvich