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Evgeny L Styskin

Alexandr G Liakumovich

Yakov Abramovich Gurvich

Simona T Kumok

Jury Ivanovich Michurov

Grigory I Rutman

Olga Fedorovna Starikova

Vladimir A Yanshevsky

Vladimir Avgustovich Yanshevsky

Jury I Michurov

Alexandr Afroimovich Grinberg

Vladimir K Gusev

Galina G Latysheva

Anna I Rybak

Rufina A Filipova

Grigory Iosifich Rutman

Igor J Logutov

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

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)

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Moscow, Russia

Evgeny L Styskin