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US3895076A
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US
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Process for the preparation of monomethylethers of dihydroxybenzene
Assignee: Haarmann and Reimer GmbH
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Filing: 1972-08-02
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Granted: 1975-07-15
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Expires: 1992-08-02
Abstract
Abstract Monomethylethers of an unsubstituted or symmetrically substituted dihydroxybenzene are prepared by reacting the dihydroxybenzene with methanol in the liquid phase at a temperature from 200*C to 240*C in the presence of boron phosphate as a catalyst.
Inventors
- 👤 Kurt Bauer
- 👤 Reiner Molleken
- 👤 Rudolf Hopp
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 04:39
CPC Classifications
C; C07; C07C; C07C41/00; C07C41/01; C07C41/09
Claims Analysis
Total Claims: 20
Claim 1
Independent Claim
95 words
PROCESS FOR THE PREPARATION OF A MONOMETHYLETHER OF UNSUBSTITUTED OR SYMMETRICALLY LOWER ALKYL-SUBSTITUTED DIHYDROXYBENZENE SELECTED FROM PYROCATECHOL, RESORCINOL, HYDROQUINONE AND SYMMETRICALLY ALKYL-SUBSTITUTED DIHYDROXYBENZENE WHEREIN EACH LOWER ALKYL SUBSTITUENT CONTAINS UP TO 2 CARBON ATOMS, WHICH PROCESS COMPRISES CONTINUOUSLY INTRODUCING THE DIHYDROXYBENZENE TO BE ETHERIFIED AND METHANOL INTO A REACTOR AND MAINTAINING THEM THEREIN IN THE LIQUID PHASE AT A TEMPERATURE IN THE RANGE OF FROM 200*C TO 240*C IN THE PRESENCE OF A CATALYST CONSISTING ESSENTIALLY OF BORON PHOSPHATE, CONTINUOUSLY WITHDRAWING ETHER, UNREACTED METHANOL AND UNREACTED DIHYDROXYBENZENE AND RECYCLING TO THE REACTOR UNREACTED DIHYDROXYBENZENE CONTINUOUSLY.
Claim 2
Dependent Claim
95 words
PROCESS FOR THE PREPARATION OF A MONOMETHYLETHER OF UNSUBSTITUTED OR SYMMETRICALLY LOWER ALKYL-SUBSTITUTED DIHYDROXYBENZENE SELECTED FROM PYROCATECHOL, RESORCINOL, HYDROQUINONE AND SYMMETRICALLY ALKYL-SUBSTITUTED DIHYDROXYBENZENE WHEREIN EACH LOWER ALKYL SUBSTITUENT CONTAINS UP TO 2 CARBON ATOMS, WHICH PROCESS COMPRISES CONTINUOUSLY INTRODUCING THE DIHYDROXYBENZENE TO BE ETHERIFIED AND METHANOL INTO A REACTOR AND MAINTAINING THEM THEREIN IN THE LIQUID PHASE AT A TEMPERATURE IN THE RANGE OF FROM 200*C TO 240*C IN THE PRESENCE OF A CATALYST CONSISTING ESSENTIALLY OF BORON PHOSPHATE, CONTINUOUSLY WITHDRAWING ETHER, UNREACTED METHANOL AND UNREACTED DIHYDROXYBENZENE AND RECYCLING TO THE REACTOR UNREACTED DIHYDROXYBENZENE CONTINUOUSLY.
Claim 3
Dependent Claim
15 words
Process as claimed in claim 1 wherein each lower alkyl substituent contains two carbon atoms.
Claim 4
Dependent Claim
12 words
Process as claimed in claim 1 wherein the unsubstituted dihydroxybenzene is pyrocatechol.
Claim 5
Dependent Claim
12 words
Process as claimed in claim 1 wherein the unsubstituted dihydroxybenzene is resorcinol.
Claim 6
Dependent Claim
12 words
Process as claimed in claim 1 wherein the unsubstituted dihydroxybenzene is hydroquinone.
Claim 7
Dependent Claim
12 words
Process as claimed in claim 1 wherein said dihydroxybenzene is dimethyl substituted.
Claim 8
Dependent Claim
14 words
Process as claimed in claim 1 wherein the dihydroxybenzene is 3,6-dimethyl-pyrocatechol, 3,6-diethyl-pyrocatechol, 4,5-dimethyl-pyrocatechol, 4,5-diethyl-pyrocatechol.
Claim 9
Dependent Claim
26 words
Process as claimed in claim 1 wherein said dihydroxybenzene is 2-methyl or 2-ethyl resorcinol, 5-methyl or 5-ethyl resorcinol, 2,5-dimethyl or 2,5-diethyl resorcinol, 4,6-dimethyl or 4,6-diethyl resorcinol.
Claim 10
Dependent Claim
15 words
Process as claimed in claim 1 wherein said dihydroxybenzene is 2,3-dimethyl-hydroquinone, 2,3-diethyl-hydroquinone, 2,5-dimethyl-hydroquinone or 2,5-diethyl-hydroquinone.
Claim 11
Dependent Claim
24 words
Process as claimed in claim 1 wherein the mole ratio of dihydroxybenzene to methanol is in the range of from 1:0.1 to 1: 50.
Claim 12
Dependent Claim
23 words
Process as claimed in claim 10 wherein the mole ratio of dihydroxybenzene to methanol is in the range of from 1:1 to 1:7.
Claim 13
Dependent Claim
20 words
Process as claimed in claim 1 wherein the reaction is carried out at a temperature of from 220*C to 240*C.
Claim 14
Dependent Claim
16 words
Process as claimed in claim 1 wherein the boron phosphate is supported on a carrier material.
Claim 15
Dependent Claim
13 words
Process as claimed in claim 13 wherein the carrier material is silica gel.
Claim 16
Dependent Claim
24 words
Process as claimed in claim 1 wherein the catalyst is used in an amount of 0.01 to 5.0 moles per mole of dihydroxy benzene.
Claim 17
Dependent Claim
23 words
A process according to claim 1 wherein water of reaction is removed from the reaction mixture comprising the dihydroxybenzene and methanol by distillation.
Claim 18
Dependent Claim
77 words
A process for the preparation of a monomethylether of an unsubstituted or symmetrically lower alkyl-substituted dihydroxybenzene selected from pyrocatechol, resorcinol, hydroquinone and symmetrically alkyl-substituted dihydroxybenzene wherein each lower alkyl substituent contains up to 2 carbon atoms, which process comprises reacting the dihydroxybenzene to be etherified with methanol in a liquid phase at a super atmospheric pressure at a temperature in the range of 200*C to 240*C in the presence of a catalyst consisting essentially of boron phosphate.
Claim 19
Dependent Claim
77 words
A process for the preparation of a monomethylether of an unsubstituted or symmetrically lower alkyl-substituted dihydroxybenzene selected from pyrocatechol, resorcinol, hydroquinone and symmetrically alkyl-substituted dihydroxybenzene wherein each lower alkyl substituent contains up to 2 carbon atoms, which process comprises reacting the dihydroxybenzene to be etherified with methanol in a liquid phase at a super atmospheric pressure at a temperature in the range of 200*C to 240*C in the presence of a catalyst consisting essentially of boron phosphate.
Claim 20
Dependent Claim
17 words
A process according to claim 17 wherein the dihydroxybenzene is reacted with the methanol under autogenous pressure.
References Cited (Backward Citations)
US3689570A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-07-14 | 1979-01-13 | 1979-07-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-07-14 | 1983-01-13 | 1983-07-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-07-14 | 1987-01-13 | 1987-07-15 | $7700.00 | Window Closed / Lapsed |