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US5166423A
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Process for the oxidation of alcohols to acids
Assignee: Shell USA Inc
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Filing: 1991-08-30
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Granted: 1992-11-24
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Expires: 2011-08-30
Abstract
Abstract A process for the preparation of an alkanoic acid which comprises reacting the corresponding alkanol with a solubilized stable free radical nitroxide having the formula: ##STR1## wherein each of R 1 , R 2 , R 3 and R 4 is an alkyl, aryl or heteroatom substituted alkyl group having 1 to about 15 carbon atoms and each of R 5 and R 6 is alkyl, hydrogen, aryl or a substituted heteroatom, and nitric acid in the presence of an oxidant at a temperature in the range of from about 25° C. to about 65° C. and thereafter separating out the alkanoic acid.
Inventors
- 👤 Herbert E. Fried
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 08:15
CPC Classifications
C; C07; C07C; C07C51/00; C07C51/16; C07C51/27
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
103 words
A process for the preparation of an alkanoic acid which comprises reacting the corresponding alkanol with a solubilized stable free radical nitroxide having the formula: ##STR5## wherein each of R 1 , R 2 , R 3 and R 4 is an alkyl, aryl or heteroatom substituted alkyl group having 1 to about 15 carbon atoms and each of R 5 and R 6 is alkyl, hydrogen, aryl or a substituted heteroatom, and nitric acid in the presence of an oxidant at a temperature in the range of from about 25° C. to about 65° C. and thereafter separating out the alkanoic acid.
Claim 2
Dependent Claim
103 words
A process for the preparation of an alkanoic acid which comprises reacting the corresponding alkanol with a solubilized stable free radical nitroxide having the formula: ##STR5## wherein each of R 1 , R 2 , R 3 and R 4 is an alkyl, aryl or heteroatom substituted alkyl group having 1 to about 15 carbon atoms and each of R 5 and R 6 is alkyl, hydrogen, aryl or a substituted heteroatom, and nitric acid in the presence of an oxidant at a temperature in the range of from about 25° C. to about 65° C. and thereafter separating out the alkanoic acid.
Claim 3
Dependent Claim
27 words
The process of claim 1 wherein the solubilized stable free radical nitroxide is selected from the group consisting of 2,2,6,6-tetramethyl-piperidine-1-oxyl, 4-hydroxy-2,2,6,6-tetramethyl-piperidine-1-oxyl, 4-alkoxy-2,2,6,6-tetramethyl-piperidine-1-oxyl, 4-oxo-2,2,6,6-tetramethyl-piperidine-1-oxyl, 2,2,6,6-tetramethyl-piperidine-1-oxyl-4-sulfate, and mixtures thereof.
Claim 4
Dependent Claim
25 words
The process of claim 2 wherein the solubilized stable free radical nitroxide is selected from the group consisting of 2,2,6,6-tetramethyl-piperidine-1-oxyl, 2,2,6,6-tetramethyl-piperidine-1-oxyl-4-sulfate, 4-alkoxy-2,2,6,6-tetramethyl-piperidine-1-oxyl and mixtures thereof.
Claim 5
Dependent Claim
34 words
The process of claim 1 wherein the stable free radical nitroxide is dissolved in a solvent selected from the group consisting of acetonitrile, tertiary butyl alcohol, tertiary amyl alcohol, ethyl acetate and mixtures thereof.
Claim 6
Dependent Claim
29 words
The process of claim 4 wherein the stable free radical nitroxide is dissolved in a solvent selected from the group consisting of tertiary butyl alcohol acetonitrile, and mixtures thereof.
Claim 7
Dependent Claim
24 words
The process of claim 1 wherein said nitric acid has a concentration in the range of from about 50 percent to about 100 percent.
Claim 8
Dependent Claim
16 words
The process of claim 6 wherein said nitric acid has a concentration of about 70 percent.
Claim 9
Dependent Claim
29 words
The process of claim 1 wherein said alkanol is contacted with said solubilized stable free radical nitroxide, followed by the addition thereto of said nitric acid and said oxidant.
Claim 10
Dependent Claim
37 words
The process of claim 8 wherein the amount of solubilized stable free radical nitroxide is in the range of from about 1 mole percent to about 50 mole percent, basis the number of moles of starting alkanol.
Claim 11
Dependent Claim
37 words
The process of claim 8 wherein the amount of solubilized stable free radical nitroxide is in the range of from about 5 mole percent to about 30 mole percent basis the number of moles of starting alkanol.
Claim 12
Dependent Claim
34 words
The process of claim 8 wherein the amount of nitric acid is in the range of from about 5 mole percent to about 100 mole percent, basis the number of moles of starting alkanol.
Claim 13
Dependent Claim
12 words
The process of claim 1 wherein said oxidant is an oxygen-containing gas.
Claim 14
Dependent Claim
20 words
The process of claim 12 wherein said oxygen-containing gas is selected from the group consisting of pure oxygen and air.
Claim 15
Dependent Claim
12 words
The process of claim 13 wherein said oxygen-containing gas is pure oxygen.
Claim 16
Dependent Claim
30 words
The process of claim 1 wherein said process is carried out at a temperature in the range of from about 30° C. to about 45° C. and at atmospheric pressure.
Claim 17
Dependent Claim
30 words
The process of claim 15 wherein said process is carried out at a temperature in the range of from about 35° C. to about 40° C. and at atmospheric pressure.
References Cited (Backward Citations)
US4620033A
Cited
JPH0596516A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
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| 3.5 Years (Year 4) | 1995-11-24 | 1996-05-25 | 1996-11-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1999-11-24 | 2000-05-25 | 2000-11-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2003-11-24 | 2004-05-25 | 2004-11-24 | $7700.00 | Window Closed / Lapsed |