US4112006A
Expired / Lapsed
US
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Process for nitrating toluene
Assignee: Hoechst AG
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Filing: 1977-07-15
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Granted: 1978-09-05
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Expires: 1997-07-15
Abstract
Abstract Toluene is nitrated with nitric acid in the gaseous phase under reduced pressure and at temperatures from about 80° - 180° C, while using an acidic inorganic catalyst consisting of a carrier substance based on SiO 2 and/or Al 2 O 3 impregnated with a high boiling inorganic acid such as H 2 SO 4 or H 3 PO 4 and optionally with metal salts of such acids. This process yields essentially p-nitrotoluene, in addition to a smaller quantity of o-nitrotoluene and a very small amount of m-isomer. The technology of the process is simple and provides good yields. The nitrotoluenes, especially the p,nitrotoluene are interesting intermediates, for example for the manufacture of dyestuffs.
Inventors
- 👤 Hans Schubert
- 👤 Friedrich Wunder
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 16:34
CPC Classifications
B; B01; B01J; B01J37/00; B01J37/02; B01J37/0201; C; C07; C07C; C07C201/00; C07C201/06; C07C201/08
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
70 words
A process for the production of p-nitrotoluene which comprises reacting toluene with nitric acid in the gaseous phase under reduced pressure and at a temperature of about 80° to 180° C. in the presence of an inorganic catalyst which consists essentially of a carrier substance based on SiO 2 and/or Al 2 O 3 impregnated with a high boiling inorganic acid and optionally with metal salts of such an acid.
Claim 2
Dependent Claim
70 words
A process for the production of p-nitrotoluene which comprises reacting toluene with nitric acid in the gaseous phase under reduced pressure and at a temperature of about 80° to 180° C. in the presence of an inorganic catalyst which consists essentially of a carrier substance based on SiO 2 and/or Al 2 O 3 impregnated with a high boiling inorganic acid and optionally with metal salts of such an acid.
Claim 3
Dependent Claim
30 words
A process according to claim 1, wherein the reaction is carried out under a pressure of about 1 to 10 mm Hg, preferably of about 20 to 50 mm Hg.
Claim 4
Dependent Claim
21 words
A process according to claim 2, wherein the reaction is carried out at temperatures of from about 100° to 140° C.
Claim 5
Dependent Claim
23 words
A process according to claim 1, wherein the carrier substance is impregnated with H 2 SO 4 or H 3 PO 4 .
Claim 6
Dependent Claim
42 words
A process according to claim 1, wherein the carrier substance is impregnated with H 2 SO 4 and a sulfate with a trivalent metal cation, preferably with Fe 2 (SO 4 ) 3 and/or with Al 2 (SO 4 ) 3 .
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1981-09-04 | 1982-03-06 | 1982-09-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-09-04 | 1986-03-06 | 1986-09-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-09-04 | 1990-03-06 | 1990-09-05 | $7700.00 | Window Closed / Lapsed |