4773-40-4Relevant academic research and scientific papers
Production of bisphenol monoester
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, (2008/06/13)
A bisphenol monoester represented by the formula (I): STR1 wherein R1 is hydrogen or alkyl, R2 and R3 are each alkyl, and R4 is alkyl, alkenyl or phenyl, is produced by continuous two step reactions in which an aldehyde R1 -CHO and 2,4-dialkylphenol are subjected to a condensation reaction in a C6 -C10 aliphatic or C6 -C12 aromatic hydrocarbon solvent, and then a resulting bisphenol compound dissolved in the solvent is subjected to an esterification with a carboxylic acid R4 --COOH or its derivative. Prior to the esterification, the organic layer containing the bisphenol compound is subjected to a dehydration treatment, thereby enabling the two steps to proceed continuously without isolating the intermediate bisphenol compound. A purification process for the bisphenol monoester of the formula (I) is also disclosed in which the monoester is purified from a mixed solvent comprising a C6 -C12 aromatic hydrocarbon solvent and a C1 -C8 alcohol or C2 -C3 aliphatic nitrile solvent.
Method for preparing sterically hindered bis- or polyphenols
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, (2008/06/13)
A method for preparing sterically hindered bis- or polyphenols of the formula: STR1 wherein R' is hydrogen, a C1 -C4 alkyl; R" and R"' the same or different and are each: STR2 wherein R is a tertiary C4 -C8 alkyl, R1 and R2 are the same or different and represent a C1 -C8 alkyl or a C6 -C8 cycloalkyl, or a C7 -C9 aralkyl, which comprises reacting the starting sterically hindered 2,4,6-trialkylphenols of the formula: STR3 wherein A is a C1 -C8 alkyl or a C6 -C8 cycloalkyl or a C7 -C9 aralkyl or a 3,5-dialkyl-2-hydroxybenzyl of the formula: STR4 B is a C1 -C8 alkyl, or a C6 -C8 cycloalkyl, or a C7 -C9 aralkyl, or a 3,5-dialkyl-4-hydroxybenzyl of the formula: STR5 wherein R1 and R are as identified above, with acetals, aldehydes or donors of C1 -C5 aldehydes in an acidic medium at a temperature within the range of from 60° to 200° 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.
