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US4853488A Expired / Lapsed US ⏱️ 0.0 years remaining

Process for the preparation of (2,2)-paracyclophane and derivatives thereof

Assignee: Montedison SpA
•
Filing: 1988-04-08
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Granted: 1989-08-01
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Expires: 2008-04-08
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Abstract

Abstract Process for the preparation of (2,2)-paracyclophane or derivatives thereof by the Hofmann elimination of p-methylbenzyl-trimethylammonium hydroxide or derivatives thereof, in an aqueous solution of an alkali metal hydroxide, wherein said elimination is carried out in the presence of a compound of the formula (I): (R).sub.m --A--(X).sub.n (I) wherein A represents an aromatic group, X an electron donor group, R hydrogen or an alkyl group containing from 1 to 4 carbon atoms, n is an integer from 1 to 6, and m is zero or an integer from 1 up to a value such that the sum m+n is equal to the number of substitutable positions in the aromatic group.

Inventors

  • 👤 Raffaele Ungarelli
  • 👤 Loris Sogli

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-30 10:25
CPC Classifications
C; C07; C07C; C07C13/00; C07C13/28; C07C13/32; C07C13/70; C07C1/00; C07C1/32; C07C1/321; C07C1/323; C07C2603/00; C07C2603/92

Claims Analysis

Total Claims: 8
Claim 1
Independent Claim 241 words
A process for preparing (2,2)-paracyclophane and derivatives thereof of the formula: ##STR3## wherein B is a halogen atom, an alkyl radical, an aralkyl radical, or a halo-aralkyl radical, having up to 20 carbon atoms, and p is zero or an integer from 1 to 4, by the Hofmann elimination of a p-methylbenzyltrimethyl-ammonium derivative of the formula: ##STR4## wherein B and p are the same as defined hereinabove, and Y is a hydroxy radical or a halogen atom, in an alkaline aqueous solution, characterized in that said elimination is carried out at a temperature of 50° to 150° C. and in the presence of at least a catalytic amount of a compound having the formula: (R).sub.m --A--(X).sub.n (I) wherein A is an aromatic group, X is an electron donor group, R is a hydrogen atom or an alkyl radical having from 1 to 4 carbon atoms, n is an integer from 1 to 6, and m is zero or an integer from 1 up to a value such that the sum m+n is equal to the number of substitutable positions in the aromatic group A, and wherein the electron-donor group X is selected from the group consisting of --OR 1 , --N(R 1 ) 2 and --SR 1 , and wherein R 1 is hydrogen, an alkyl radical having from 1 to 6 carbon atoms, an aryl radical, an alkyl-aryl radical, or an arylalkyl radical containing from 6 to 18 carbon atoms.
Claim 2
Dependent Claim 241 words
A process for preparing (2,2)-paracyclophane and derivatives thereof of the formula: ##STR3## wherein B is a halogen atom, an alkyl radical, an aralkyl radical, or a halo-aralkyl radical, having up to 20 carbon atoms, and p is zero or an integer from 1 to 4, by the Hofmann elimination of a p-methylbenzyltrimethyl-ammonium derivative of the formula: ##STR4## wherein B and p are the same as defined hereinabove, and Y is a hydroxy radical or a halogen atom, in an alkaline aqueous solution, characterized in that said elimination is carried out at a temperature of 50° to 150° C. and in the presence of at least a catalytic amount of a compound having the formula: (R).sub.m --A--(X).sub.n (I) wherein A is an aromatic group, X is an electron donor group, R is a hydrogen atom or an alkyl radical having from 1 to 4 carbon atoms, n is an integer from 1 to 6, and m is zero or an integer from 1 up to a value such that the sum m+n is equal to the number of substitutable positions in the aromatic group A, and wherein the electron-donor group X is selected from the group consisting of --OR 1 , --N(R 1 ) 2 and --SR 1 , and wherein R 1 is hydrogen, an alkyl radical having from 1 to 6 carbon atoms, an aryl radical, an alkyl-aryl radical, or an arylalkyl radical containing from 6 to 18 carbon atoms.
Claim 3
Dependent Claim 55 words
The process according to claim 1, wherein in the compound of formula (I) A represents a phenyl or naphthyl group, n is equal to 2 or 3, m is zero or an integer from 1 to 3, and X has the values reported in claim 1, which may be equal or different from each other.
Claim 4
Dependent Claim 40 words
The process according to claim 1, characterized in that the compound of formula (I) is selected from the group consisting of: 1,4-hydroquinone; ortho-, meta- and paraaminophenol; ortho-, meta- and para-phenylene-diamine; 2,6-ditert.butyl-para-cresol; p.p.'-di-amino-di-phenylmethane; phenol; N,N'-di-phenyl-1,4-phenylene diamine; 3-tert.butyl-4-hydroxy-anisole; 2,4-di-tert.butyl-phenol; and hydroquinone-monomethyl ether.
Claim 5
Dependent Claim 39 words
The process according to claim 1, characterized in that the catalyst of formula (I) is used in a molar amount ranging from 5 to 30% based on the p-methylbenzyltrimethylammonium derivative of formula (III), and preferably from 10 to 20%.
Claim 6
Dependent Claim 40 words
The process according to claim 1, characterized in that the concentration of the aqueous solution of alkali metal hydroxide is higher than 10% by weight and is maintained, during the Hofmann elimination reaciton, at from 20 to 50% by weight.
Claim 7
Dependent Claim 36 words
The process according to claim 1, characterized in that the p.methylbenzyltrimethylammonium hydroxide of formula (III) is prepared in situ by the reaction of the corresponding halide with the alkali metal hydroxide present in the reaction medium.
Claim 8
Dependent Claim 44 words
The process according to claim 1, characterized in that the Hofmann elimination is carried out at a temperature between 90° and 130° C., over the course of 1 to 50 hours, preferably 2 to 10 hours, and preferably in the absence of a solvent.

References Cited (Backward Citations)

US4783561A Cited
US4795838A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1992-07-31 1993-01-30 1993-08-01 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1996-07-31 1997-01-30 1997-08-01 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2000-07-31 2001-01-30 2001-08-01 $7700.00 Window Closed / Lapsed

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