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US4994580A Expired / Lapsed US ⏱️ 0.0 years remaining

Producing bis (alicyclic) thioethers

Assignee: Albemarle Corp
•
Filing: 1989-10-26
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Granted: 1991-02-19
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Expires: 2009-10-26
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Abstract

Abstract 3,3'-Thiobis(2,5-dihydrothiophene-1,1-dioxides) on heating with a reactive Diels-Alder dienophile undergo a reaction producing thioethers having two six-membered alicyclic rings in the molecule, such as 4,4'-thiobis(3,6-dihydrophthalic acids) or the esters, anhydrides or imides thereof, and 4,4'-thiobis(1,2,3,6-tetrahydrophthalic acids) or the esters, anhydrides or imides thereof. Both rings of the dihydrothiophene dioxides participate in the reaction, apparently by forming a tetraene structure which co-reacts with two equivalents of the dienophile to form an adduct in which each six-membered ring has one or two olefinic double bonds. During the course of the reaction, the thioether bridge remains intact. Some of the bis(alicyclic) thioethers are readily converted to the corresponding bis(aromatic)thioethers by use of known aromatization methods and systems. Various utilities for the products of the foregoing reactions are described.

Inventors

  • 👤 G. Patrick Stahly

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-08 11:25
CPC Classifications
C; C07; C07D; C07D209/00; C07D209/02; C07D209/44; C07D209/48; C07D307/00; C07D307/77; C07D307/87; C07D307/89

Claims Analysis

Total Claims: 3
Claim 1
Independent Claim 17 words
A process of producing 4,4'-thiobis(N-arylphthalimide) compounds which comprises aromatizing a 4,4'-thiobis(N-aryltetrahydrophthalimide) using dimethylsulfoxide, iodine and sulfuric acid.
Claim 2
Dependent Claim 17 words
A process of producing 4,4'-thiobis(N-arylphthalimide) compounds which comprises aromatizing a 4,4'-thiobis(N-aryltetrahydrophthalimide) using dimethylsulfoxide, iodine and sulfuric acid.
Claim 3
Dependent Claim 11 words
The process of claim 1 wherein said aryl substituent is phenyl.

References Cited (Backward Citations)

US3989712A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1994-02-18 1994-08-20 1995-02-19 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1998-02-18 1998-08-20 1999-02-19 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2002-02-18 2002-08-20 2003-02-19 $7700.00 Window Closed / Lapsed

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