Process for the preparation of dicyclopentylene [2,2'-bis(4-alkyl-6-t-butylphenols)]
AssigneeChemische Werke Lowi GmbH
InventorsRolf Muller, Werner Hartmann, Zdenek Kuca
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Abstract
The invention concerns a process for the preparation of dicyclopentylene [2,2'-bis(4-alkyl-6-t-butylphenols)] of the formula I ##STR1## wherein R.sub.1 is tertiary butyl and R.sub.2 is methyl or ethyl, by the reaction of 1.5 to 2.5 moles of a 4-alkyl-6-t-butyl-phenol of the formula II ##STR2## wherein R.sub.1 and R.sub.2 are as defined above, with 0.8 to 1.2 moles dicyclopentadiene at a temperature between 20.degree. and 120.degree. C. in the presence of an organic solvent and borontrifluoride or a complex thereof as catalyst, characterised by employment of specially selected solvents and reaction under practically anhydrous conditions.
Claims9
A process for the preparation of dicyclopentylene [2,2'-bis(4-alkyl-6-t-butylphenols)] of the formula I ##STR7## wherein R.sub.1 is tertiary butyl and
- R.sub.2 is methyl or ethyl,
- by the reaction of 1.5 to 2.5 moles of a 4-alkyl-6-t-butyl-phenol of the formula II ##STR8## wherein R.sub.1 and R.sub.2 are as defined above, with 0.8 to 1.2 moles dicyclopentadiene at a temperature between 20.degree. and 120.degree. C. in the presence of an organic solvent and borontrifluoride or a complex thereof as catalyst, characterised in that the solvent is selected from:
- (a) an aromatic solvent which does not enter into any significant trans-alkylation with the tertiary butyl group of the 4-alkyl-6-t-butyl-phenol under the reaction conditions in the presence of the catalyst,
- (b) a non-aromatic solvent which does not possess significant nucleophilic properties which strongly reduces or practically eliminates the activity of the catalyst, or
- (c) a mixture of (a) and (b)
- and that the reaction is carried out under practically anhydrous conditions.
Dependencies are inferred from the claim text.