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US 4,734,533 AGranted
Process for the preparation of (2,2)-paracyclophane and derivatives thereof
AssigneeMontedison S.p.A.
InventorsRaffaele Ungarelli, Maurizio A. Beretta, Alessandro Malacrida, Loris Sogli
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Abstract
Process for the preparation of (2,2)-paracyclophane or derivatives thereof by the Hofmann elimination of p.-methylbenzyltrimethylammonium hydroxide or derivatives thereof, in an aqueous solution of an alkali metal hydroxide, wherein said elimination is carried out in the presence of a ketone of the formula: Ch.sub.3 --CO--CH.sub.2 --R (I) wherein R is hydrogen, a halogen, or an alkyl-carboxylic group.
Claims11
A process for preparing (2,2)-paracyclophane and derivatives thereof of the formula:
- ##STR5## wherein X is a halogen atom, an alkyl radical, an aralkyl radical, or a halo-aralkyl radical, and n is zero or an integer from 1 to 4, by the Hofmann elimination of p.methylbenzyltrimethylammonium hydroxide or derivatives thereof of the formula:
- ##STR6## wherein X and n are the same as defined hereinabove, in an aqueous solution of an alkali metal hydroxide, characterized in that said elimination is carried out at a temperature between 50.degree. and 150.degree. C., and in the presence of at least a catalytic amount of a ketone having the formula:
- CH.sub.3 --CO--CH.sub.2 --R (I)
- wherein R is hydrogen, halogen, or an alkyl-carboxylic group containing 1 to 4 carbon atoms in the alkyl chain, the ketone concentration being from 0.1 to 200%, based on the p.methylbenzyltrimethylammonium hydroxide or derivatives thereof.
1 more element
Dependencies are inferred from the claim text.