EP0226225A2
Expired / Lapsed
EP
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Process for the preparation of (2,2)-paracyclophane and derivatives thereof
Assignee: Montedison SpA
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Filing: 1986-12-19
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Granted: —
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Expires: 2006-12-19
Abstract
Abstract A process for the preparation of (2,2)-paracyclophane or derivatives thereof by 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 formula: CH3 - CO - CH2 - R (I) wherein R is hydrogen, a halogen or an alkyl-carboxylic group.
Inventors
- 👤 Raffaele Ungarelli
- 👤 Maurizio Augusto Beretta
- 👤 Allessandro Malacrida
- 👤 Loris Sogli
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-09 08:54
CPC Classifications
C; C07; C07C; C07C23/00; C07C23/18; C07C23/20; C07C23/38; C07C1/00; C07C1/32; C07C1/321; C07C1/323; C07C17/00; C07C17/26; C07C17/263; C07C2603/00; C07C2603/92
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
119 words
A process for preparing (2,2)-paracyclophane and derivatives thereof of formula : wherein X is a halogen atom, an alkyl radical, an aralkyl radical or.a halogen aralkyl radical and n is zero or an integer from 1 to 4, by Hofmann elimination of p.methyl- benzyltrimethylammonium hydroxide or derivatives thereof of formula : 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 in the presence of at least catalytic amounts of a ketone having formula : wherein R is hydrogen, an atom of halogen, such as chlorine or bromine, or an alkyl-carboxylic group containing 1 to 4 carbon atoms in the alkyl chain.
Claim 2
Dependent Claim
119 words
A process for preparing (2,2)-paracyclophane and derivatives thereof of formula : wherein X is a halogen atom, an alkyl radical, an aralkyl radical or.a halogen aralkyl radical and n is zero or an integer from 1 to 4, by Hofmann elimination of p.methyl- benzyltrimethylammonium hydroxide or derivatives thereof of formula : 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 in the presence of at least catalytic amounts of a ketone having formula : wherein R is hydrogen, an atom of halogen, such as chlorine or bromine, or an alkyl-carboxylic group containing 1 to 4 carbon atoms in the alkyl chain.
Claim 3
Dependent Claim
35 words
The process according to claim 1, wherein the p.methylbenzyl trimethylammonium hydrogen of formula (III) is prepared in situ from the corresponding halide by the action of the alkali metal hydroxide present in the reaction medium.
Claim 4
Dependent Claim
16 words
The process according to claim 1 or 2, wherein the ketone of formula (I) is acetone.
Claim 5
Dependent Claim
16 words
The process according to claim 1 or 2, wherein the ketone of formula (I) is chloroacetone.
Claim 6
Dependent Claim
16 words
The process according to claim 1 or 2, wherein the ketone of formula (I) is acetylacetone.
Claim 7
Dependent Claim
19 words
The process according to any of the preceding claims, wherein the ketone of formula (I) is prepared in situ.
Claim 8
Dependent Claim
23 words
The process according to claim 6, wherein the ketone of formula (I) is prepared in situ starting from mesityl oxide or derivatives thereof.
Claim 9
Dependent Claim
22 words
The process according to claim 6, wherein the ketone of formula (I) is prepared in situ starting from diacetone-alcohol or its derivatives.
Claim 10
Dependent Claim
48 words
The process according to any of the preceding claims, wherein the amount of ketone of formula (I), of mesityl oxide or derivatives thereof or of diacetone alcohol or derivatives thereof ranges from 0.1 to 200%, and preferably from 1 to 50X by weight, referred to p.methylbenzyltri- methylammonium hydroxide.
Claim 11
Dependent Claim
34 words
The process according to any of the preceding claims, wherein the concentration of the aqueous solution of an alkali metal hydroxide is maintained, during the Hofmann elimination reaction, from 25 to 35% by weight.
Claim 12
Dependent Claim
49 words
The process according to any of the preceding claims, wherein Hofmann elimination is carried out at a temperature between 50° and 150°C, preferably between 70° and 125°C, over the course of 1-40 hours, preferably of 2-10 hours, and optionally in the presence of an inert organic solvent. Milan, Gio.
References Cited (Backward Citations)
No citation records indexed.
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