US4405812A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for ortho dealkylation of aromatic amines
Assignee: Ethyl Corp
•
Filing: 1982-02-19
•
Granted: 1983-09-20
•
Expires: 2002-02-19
Abstract
Abstract Ortho-methyl groups are preferentially removed from o-methyl substituted aromatic amines by contacting with a nickel catalyst at about 200°-400° C.
Inventors
- 👤 Walter K. Dean
- 👤 Bernard R. Meltsner
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 15:12
CPC Classifications
C; C07; C07C; C07C209/00; C07C209/68
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
43 words
A process for selectively removing an ortho-methyl substituent from an aromatic amine having at least one nuclear methyl substituent ortho to an amine group, said process comprising contacting said aromatic amine with a nickel catalyst at an elevated temperature of about 200°-400° C.
Claim 2
Dependent Claim
43 words
A process for selectively removing an ortho-methyl substituent from an aromatic amine having at least one nuclear methyl substituent ortho to an amine group, said process comprising contacting said aromatic amine with a nickel catalyst at an elevated temperature of about 200°-400° C.
Claim 3
Dependent Claim
14 words
A process of claim 2 wherein said aromatic amine is an o-methyl substituted aniline.
Claim 4
Dependent Claim
11 words
A process of claim 2 wherein said aniline is 2,5-dimethyl aniline.
Claim 5
Dependent Claim
35 words
A process of claim 2 for making m-toluidine, said process comprising contacting 2,5-dimethyl aniline with a nickel catalyst at an elevated temperature of about 300°-375° C. whereby the 2-methyl group is preferentially removed forming m-toluidine.
Claim 6
Dependent Claim
54 words
A process for making m-toluidine, said process comprising (a) nitrating p-xylene to form 2,5-dimethyl nitrobenzene, (b) reducing said 2,5-dimethylnitrobenzene to form 2,5-dimethyl aniline, (c) contacting said 2,5-dimethyl aniline with a nickel catalyst at an elevated temperature of about 200°-400° C. to selectively remove the o-methyl group and (d) recovering m-toluidine from the reaction product.
Claim 7
Dependent Claim
54 words
A process for making m-toluidine, said process comprising (a) nitrating p-xylene to form 2,5-dimethyl nitrobenzene, (b) reducing said 2,5-dimethylnitrobenzene to form 2,5-dimethyl aniline, (c) contacting said 2,5-dimethyl aniline with a nickel catalyst at an elevated temperature of about 200°-400° C. to selectively remove the o-methyl group and (d) recovering m-toluidine from the reaction product.
References Cited (Backward Citations)
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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) | 1986-09-19 | 1987-03-21 | 1987-09-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-09-19 | 1991-03-21 | 1991-09-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-09-19 | 1995-03-21 | 1995-09-20 | $7700.00 | Window Closed / Lapsed |