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US5354923A
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Process for the preparation of aromatic carbonic diesters
Assignee: Bayer AG
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Filing: 1991-11-07
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Granted: 1994-10-11
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Expires: 2011-11-07
Abstract
Abstract Carbonic diesters containing at least one aromatic ester group can be prepared from carbonic diesters containing at least one aliphatic ester group by transesterification using a phenol, titanium dioxide having a surface area of at least 20 m 2 /g as determined by the BET method being used as catalyst.
Inventors
- 👤 Norbert Schon
- 👤 Hans-Josef Buysch
- 👤 Eberhard Zirngiebl
- 👤 Jurgen Kischkewitz
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 13:27
CPC Classifications
C; C07; C07C; C07C68/00; C07C68/06
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
80 words
Process for the preparation of carbonic diesters containing at least one aromatic ester group from carbonic diesters containing at least one aliphatic ester group by catalysed transesterification with a phenol, characterised in that the catalyst used is a titanium dioxide having a surface area of at least 90 m 2 /g as determined by the BET method in an amount of 0.1 to 200% by weight, relative to the carbonic diester used, which contains at least one aliphatic ester group.
Claim 2
Dependent Claim
80 words
Process for the preparation of carbonic diesters containing at least one aromatic ester group from carbonic diesters containing at least one aliphatic ester group by catalysed transesterification with a phenol, characterised in that the catalyst used is a titanium dioxide having a surface area of at least 90 m 2 /g as determined by the BET method in an amount of 0.1 to 200% by weight, relative to the carbonic diester used, which contains at least one aliphatic ester group.
Claim 3
Dependent Claim
35 words
Process according to claim 1, characterised in that the catalyst is used in an amount of 1 to 100% by weight, relative to the carbonic diester used, which contains at least one aliphatic ester group.
Claim 4
Dependent Claim
65 words
Process according to claim 1, characterised in that carbonic diesters containing at least one aliphatic ester group of the formula R.sup.1 O--CO--OR.sup.2 are used, in which R 1 and R 2 independently of one another, denote straight-chain or branched C 1 -C 12 -alkyl or C 3 -C 8 -cycloalkyl, in which furthermore R 1 can denote substituted or unsubstituted C 6 -C 12 -aryl.
Claim 5
Dependent Claim
59 words
Process according to claim 2, characterised in that the carbonic diesters contain at least one aliphatic ester group of the formula R.sup.3 O--CO--OR.sup.4 in which R 3 and R 4 , independently of one another, denote straight-chain or branched C 1 -C 8 -alkyl, cyclopropyl, cyclopentyl or cyclohexyl, in which furthermore R 3 can denote substituted or unsubstituted phenyl.
Claim 6
Dependent Claim
124 words
Process according to claim 1, characterised in that a phenol of the formula ##STR6## in which R 5 denotes hydrogen, C 1 -C 4 -alkyl, C 2 -C 4 -alkenyl, C 1 -C 4 -alkoxy, C 5 -C 6 -cycloalkyl, phenyl, fluorine, chlorine, bromine or cyano; R 6 represents hydrogen C 1 -C 4 -alkyl, C 2 -C 4 -alkenyl, C 1 -C 4 -alkoxy, fluorine, chlorine, bromine and R 7 represents hydrogen, C 1 -C 4 -alkyl or the group ##STR7## in which X denotes a single bond, --CH 2 --, C 2 -C 5 -cycloalkylidene, oxygen, sulphur, --CO--, --SO-- or --SO 2 --, in which R 6 and R 7 together can also denote a fused benzene ring, is used for transesterification.
Claim 7
Dependent Claim
37 words
Process according to claim 1, characterised in that a phenol of the formula ##STR8## in which R 8 and R 9 , independently of one another, denote hydrogen, C 1 -C 4 -alkyl or chlorine, is used.
Claim 8
Dependent Claim
80 words
Process according to claim 1, characterised in that the phenol is a bisphenol of the formula ##STR9## in which R 10 and R 11 , independently of one another, can denote hydrogen, C 1 -C 4 -alkyl, C 2 -C 4 -alkenyl, C 1 -C 4 -alkoxy, C 5 -C 6 -cycloalkyl, fluorine, chlorine or bromine, and Y represents a single bond, --CH 2 --, --C 2 --H 5 -alkylidene, C 5 -C 6 -cycloalkylidene, sulphur or --SO 2 --.
Claim 9
Dependent Claim
19 words
Process according to claim 1, characterised in that the reaction is carried out at a temperature of 50°-300° C.
Claim 10
Dependent Claim
25 words
Process according to claim 1 wherein the catalyst is used in an amount of 2 to 50% by weight relative to the carbonic diester used.
Claim 11
Dependent Claim
17 words
Process according to claim 1 wherein the reaction is carried out at a temperature of 100°-250° C.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1997-10-10 | 1998-04-11 | 1998-10-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2001-10-10 | 2002-04-11 | 2002-10-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2005-10-10 | 2006-04-11 | 2006-10-11 | $7700.00 | Window Closed / Lapsed |