Abstract
The work is devoted to a convenient procedure of the synthesis of 2,2′- and 4,4′-methylenebisphenols with alkyl substituents in heterogeneous catalysis. This compounds were obtained with yields up to 87% by reflux of 2,4- or 2,6-dialkylphenols with HCHO in n-octane in the presence of KSF clay. We found that the antioxidant activity on DPPH test for two novel methylenebisphenols having isobornyl fragments was comparable with control drugs.
GRAPHICAL ABSTRACT
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ACKNOWLEDGMENTS
This work was performed with the support of the Russian Academy of Sciences (fundamental research of the Presidium of the RAS “Biomedical and Biomolecular Chemistry” (Project No. 09-T-3-1023). The authors are grateful to Elena N. Zainullina for registration of NMR spectra.
Notes
a Isolated yield after column chromatography on SiO2 (without conversion).
b Yield of compound 2b after synthesis in n-heptane is shown in brackets.
c Product of reaction is a mixture of two diastereomers.
d Product of reaction is a single meso-diastereomer.
e Paraformaldehyde was also added portionwise every 1.5 h (1.47 mmol per serving).
a Compound 2f was not used in AOA test because of a low solubility of sample in EtOH.
b Used as mixtures of diastereomers meso-/rac-, 1:1.