US3723444A
Expired / Lapsed
US
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Manufacturing of bipyridylium salts
Assignee: Imperial Chemical Industries Ltd
•
Filing: 1969-06-16
•
Granted: 1973-03-27
•
Expires: 1989-06-16
Abstract
Abstract A process for the manufacture of a 1,1''-disubstituted-4,4''bipyridylium salt which comprises reacting an N-substituted-4cyano pyridinium salt with ammonia or an alkali metal hydroxide and subsequently oxidizing the resulting interaction product.
Inventors
- 👤 J Colchester
- 👤 T Blundell
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 05:07
CPC Classifications
C; C07; C07D; C07D213/00; C07D213/02; C07D213/04; C07D213/06; C07D213/22
Claims Analysis
Total Claims: 33
Claim 1
Independent Claim
14 words
A process as claimed in claim 1 wherein the solvent is an aqueous medium.
Claim 2
Dependent Claim
12 words
A process as claimed in claim 2 wherein the solvent is water.
Claim 3
Dependent Claim
13 words
A process as claimed in claim 1 wherein an organic solvent is employed.
Claim 4
Dependent Claim
20 words
A process as claimed in claim 1 wherein the reaction is carried out at temperature of from 0*C to 150*C.
Claim 5
Dependent Claim
15 words
A process as claimed in claim 5 wherein the temperature is from 10*C to 100*C.
Claim 6
Dependent Claim
14 words
A process as claimed in claim 6 wherein the temperature is up to 50*C.
Claim 7
Dependent Claim
13 words
A process as claimed in claim 1 wherein the base is potassium hydroxide.
Claim 8
Dependent Claim
13 words
A process as claimed in claim 1 wherein the base is ammonium hydroxide.
Claim 9
Dependent Claim
19 words
A process as claimed in claim 1 wherein the initial pH of the reaction mixture is greater than 9.
Claim 10
Dependent Claim
21 words
A process as claimed in claim 10 wherein the pH is allowed to rise during the reaction to less than 9.
Claim 11
Dependent Claim
21 words
A process as claimed in claim 1 wherein the oxidation is carried out at a pH of from 4 to 6.
Claim 12
Dependent Claim
17 words
A process as claimed in claim 1 wherein the interaction product is oxidized by means of air.
Claim 13
Dependent Claim
15 words
A process as claimed in claim 13 wherein air is employed in conjunction with water.
Claim 14
Dependent Claim
16 words
A process as claimed in claim 13 wherein air is employed in conjunction with an acid.
Claim 15
Dependent Claim
14 words
A process as claimed in claim 1 wherein an inorganic oxidizing agent is employed.
Claim 16
Dependent Claim
15 words
A process as claimed in claim 16 wherein the oxidizing agent is a metal salt.
Claim 17
Dependent Claim
14 words
A process as claimed in claim 17 wherein the oxidizing agent is ceric sulphate.
Claim 18
Dependent Claim
16 words
A process as claimed in claim 16 wherein the oxidizing agent is an organic oxyacid anhydride.
Claim 19
Dependent Claim
15 words
A process as claimed in claim 19 wherein the inorganic oxyacid anhydride is sulphur dioxide.
Claim 20
Dependent Claim
13 words
A process as claimed in claim 16 wherein the oxidizing agent is chlorine.
Claim 21
Dependent Claim
14 words
A process as claimed in claim 1 wherein an organic oxidizing agent is employed.
Claim 22
Dependent Claim
12 words
A process as claimed in claim 22 wherein a quinone is employed.
Claim 23
Dependent Claim
21 words
A process as claimed in claim 1 wherein the interaction product is oxidized without first being isolated from the reaction mixture.
Claim 24
Dependent Claim
51 words
A process as claimed in claim 1 wherein after oxidation of the interaction product to the bipyridylium salt, the reaction mixture contains free cyanide ions and the bipyridylium cation is separated from the free cyanide ions by acidifying the reaction mixture and heating the acidified mixture to remove hydrogen cyanide gas.
Claim 25
Dependent Claim
61 words
A process as claimed in claim 1 wherein after oxidation of the interaction product to the bipyridylium salt, the reaction mixture contains free cyanide ions and the reaction mixture is treated at a pH of 7 to 12 with a water soluble alkali metal salt of amsonic acid to precipitate the bipyridylium cation form of the bipyridylium salt of amsonic acid.
Claim 26
Dependent Claim
28 words
A process as claimed in claim 26 wherein the treatment with the salt of amsonic acid is carried out at a pH in the range 7 to 12.
Claim 27
Dependent Claim
23 words
A process as claimed in claim 25 wherein a mineral acid, acetic acid or sulphur dioxide are employed to acidify the reaction mixture.
Claim 28
Dependent Claim
28 words
A process as claimed in claim 28 wherein separation of the bipyridylium cation from free cyanide ions is carried out at a temperature of from 0*C to 100*C.
Claim 29
Dependent Claim
18 words
A process as claimed in claim 1 wherein the alkyl group contains from one to four carbon atoms.
Claim 30
Dependent Claim
15 words
A process as claiMed in claim 30 wherein the N-substituted-4-cyano-pyridinium salt is an N-methyl-4-cyano-pyridinium salt.
Claim 31
Dependent Claim
15 words
A process as claimed in claim 1 wherein the N-substituted-4-cyano-pyridinium salt is an N-carbamidomethyl-4-cyanopyridinium salt.
Claim 32
Dependent Claim
27 words
A process as claimed in claim 1 wherein the pyridine nucleus of the N-substituted-4-cyano-pyridinium salt has at least one substituent in the 2-, 3-, 5- or 6-position.
Claim 33
Dependent Claim
15 words
A process as claimed in claim 1 wherein the N-substituted-4-cyano-pyridinium salt is an N-substituted-4-cyano-pyridinium chloride.
References Cited (Backward Citations)
US3405135A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-03-26 | 1976-09-25 | 1977-03-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-03-26 | 1980-09-25 | 1981-03-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-03-26 | 1984-09-25 | 1985-03-27 | $7700.00 | Window Closed / Lapsed |