US3855306A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for the preparation of 2,4,5-trimethoxybenzaldehyde
Assignee: F Hoffmann La Roche AG
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Filing: 1972-03-27
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Granted: 1974-12-17
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Expires: 1992-03-27
Abstract
Abstract Process for the preparation of 3,4,5-trimethoxybenzaldehyde from vanillin comprising the steps of bromination, hydrolysis and methylation.
Inventors
- 👤 P Wehrli
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 10:22
CPC Classifications
C; C07; C07C; C07C47/00; C07C47/52; C07C47/575; C07C45/00; C07C45/61; C07C45/63; C07C45/64; C07C45/67; C07C45/68; C07C45/70; C07C45/71
Claims Analysis
Total Claims: 26
Claim 1
Independent Claim
129 words
A PROCESS FOR THE PREPARATION OF 3,4,5TRIMETHOXYBENZALDEHYDE WHICH COMPRISES: A. ADDING A SOLUTION OF CANILLIN IN AN ACIDIC SOLVENT MEDIUM SELECTED FOM THE GROUP CONSISTING OF CONCENTRATED AQUEOUS MINERAL ACIDS AND GLACIAL ACETIC ACID TO BROMINE AT A TEMPERATURE ABOUT 0* AND ABOUT 5*C TO AFFORD 5BROMOVANILLIN; B. CONTACTING THE 5-BROMOVANILLIN PREPARED IN (A) WITH AN ALKALI METAL HYDROXIDE AND FROM ABOUT 1 TO ABOUT 10 MOLE % OF COPPER POWDER, IN WATER AT A TEMPERATURE OF FROM ABOUT 50* TO ABOUT 120*C TO AFFORD 5-HYDROXYVANILLIN; AND C. CONTACTING THE 5-HYDROXYVANILLIN PREPARED IN (B) WITH A 15 TO 25% EXCESS OF DIMETHYL SULFATE, AND A POWDERED ALKALI METAL CARBONATE, IN AN ORGANIC MEDIUM SELECTED FROM THE GROUP CONSISTING ACETONE, METHYL ETHYL KETONE, TETRAHYDROFURAN, DIOXANE, HEXANE, HEPTANE, BENZENE AND TOLUENE.
Claim 2
Dependent Claim
129 words
A PROCESS FOR THE PREPARATION OF 3,4,5TRIMETHOXYBENZALDEHYDE WHICH COMPRISES: A. ADDING A SOLUTION OF CANILLIN IN AN ACIDIC SOLVENT MEDIUM SELECTED FOM THE GROUP CONSISTING OF CONCENTRATED AQUEOUS MINERAL ACIDS AND GLACIAL ACETIC ACID TO BROMINE AT A TEMPERATURE ABOUT 0* AND ABOUT 5*C TO AFFORD 5BROMOVANILLIN; B. CONTACTING THE 5-BROMOVANILLIN PREPARED IN (A) WITH AN ALKALI METAL HYDROXIDE AND FROM ABOUT 1 TO ABOUT 10 MOLE % OF COPPER POWDER, IN WATER AT A TEMPERATURE OF FROM ABOUT 50* TO ABOUT 120*C TO AFFORD 5-HYDROXYVANILLIN; AND C. CONTACTING THE 5-HYDROXYVANILLIN PREPARED IN (B) WITH A 15 TO 25% EXCESS OF DIMETHYL SULFATE, AND A POWDERED ALKALI METAL CARBONATE, IN AN ORGANIC MEDIUM SELECTED FROM THE GROUP CONSISTING ACETONE, METHYL ETHYL KETONE, TETRAHYDROFURAN, DIOXANE, HEXANE, HEPTANE, BENZENE AND TOLUENE.
Claim 3
Dependent Claim
15 words
The process of claim 1, wherein the acidic solvent medium is 48% aqueous hydrobromic acid.
Claim 4
Dependent Claim
13 words
The process of claim 1 wherein the alkali metal hydroxide is sodium hydroxide.
Claim 5
Dependent Claim
13 words
The process of claim 1 wherein about 3 mole % copper is utilized.
Claim 6
Dependent Claim
19 words
The process of claim 1 wherein the 5-hydroxyvanillin is isolated by hot liquid-liquid extraction with a water-immiscible organic solvent.
Claim 7
Dependent Claim
12 words
The process of claim 5 wherein the water-immiscible organic solvent comprises toluene.
Claim 8
Dependent Claim
13 words
The process of claim 1 wherein the alkali metal carbonate is sodium carbonate.
Claim 9
Dependent Claim
14 words
The process of claim 1 wherein the organic medium in step (c) comprises acetone.
Claim 10
Dependent Claim
18 words
The process of claim 1 wherein the temperature in step (c) is between about 40* and about 120*C.
Claim 11
Dependent Claim
16 words
The process of claim 9 wherein the temperature is the reflux temperature of the reaction medium.
Claim 12
Dependent Claim
44 words
A process for the preparation of 5-bromovanillin which comprises adding a solution of vanillin in an acidic solvent medium selected from the group consisting of concentrated aqueous mineral acids and glacial acetic acid to bromine at a temperature between about 0* and about 5*C.
Claim 13
Dependent Claim
44 words
A process for the preparation of 5-bromovanillin which comprises adding a solution of vanillin in an acidic solvent medium selected from the group consisting of concentrated aqueous mineral acids and glacial acetic acid to bromine at a temperature between about 0* and about 5*C.
Claim 14
Dependent Claim
16 words
The process of claim 11 wherein the acidic solvent medium is 48% percent aqueous hydrobromic acid.
Claim 15
Dependent Claim
40 words
A process for the preparation of 5-hydroxyvanillin which comprises contacting 5-bromovanillin with an alkali metal hydroxide and from about 1 to about 10 mole % of copper powder in water at a temperature of from about 50* to about 120*C.
Claim 16
Dependent Claim
40 words
A process for the preparation of 5-hydroxyvanillin which comprises contacting 5-bromovanillin with an alkali metal hydroxide and from about 1 to about 10 mole % of copper powder in water at a temperature of from about 50* to about 120*C.
Claim 17
Dependent Claim
13 words
The process of claim 11 wherein the alkali metal hydroxide is sodium hydroxide.
Claim 18
Dependent Claim
12 words
The process of claim 13 wherein about 3 mole% copper is utilized.
Claim 19
Dependent Claim
19 words
The process of claim 13 wherein the 5-hydroxyvanillin is isolated by hot liquid-liquid extraction with a water-immiscible organic solvent.
Claim 20
Dependent Claim
13 words
The process of claim 16 wherein the water immiscible organic solvent comprises toluene.
Claim 21
Dependent Claim
47 words
A process for the preparation of 3,4,5-trimethoxybenzaldehyde which comprises contacting 5-hydroxyvanillin with a 15 to 25% excess of dimethyl sulfate, and a powdered alkali metal carbonate, in an organic medium selected from the group consisting of acetone, methyl ethyl ketone, tetrahydrofuran, dioxane, hexane, heptane, benzene and toluene.
Claim 22
Dependent Claim
47 words
A process for the preparation of 3,4,5-trimethoxybenzaldehyde which comprises contacting 5-hydroxyvanillin with a 15 to 25% excess of dimethyl sulfate, and a powdered alkali metal carbonate, in an organic medium selected from the group consisting of acetone, methyl ethyl ketone, tetrahydrofuran, dioxane, hexane, heptane, benzene and toluene.
Claim 23
Dependent Claim
13 words
The process of claim 18 wherein the alkali metal carbonate is sodium carbonate.
Claim 24
Dependent Claim
11 words
The process of claim 18 wherein the organic medium comprises acetone.
Claim 25
Dependent Claim
15 words
The process of claim 18 wherein the temperature is between about 40* and about 120*C.
Claim 26
Dependent Claim
16 words
The process of claim 21 wherein the temperature is the reflux temperature of the reaction medium.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-12-16 | 1978-06-17 | 1978-12-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-12-16 | 1982-06-17 | 1982-12-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-12-16 | 1986-06-17 | 1986-12-17 | $7700.00 | Window Closed / Lapsed |