CA1052792A - Method for preparing bis-(2-pyridyl-1-oxide) disulfide - Google Patents
Method for preparing bis-(2-pyridyl-1-oxide) disulfideInfo
- Publication number
- CA1052792A CA1052792A CA223,892A CA223892A CA1052792A CA 1052792 A CA1052792 A CA 1052792A CA 223892 A CA223892 A CA 223892A CA 1052792 A CA1052792 A CA 1052792A
- Authority
- CA
- Canada
- Prior art keywords
- oxide
- alkali metal
- disulfide
- pyridyl
- hydrogen peroxide
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
Classifications
-
- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07D—HETEROCYCLIC COMPOUNDS
- C07D213/00—Heterocyclic compounds containing six-membered rings, not condensed with other rings, with one nitrogen atom as the only ring hetero atom and three or more double bonds between ring members or between ring members and non-ring members
- C07D213/02—Heterocyclic compounds containing six-membered rings, not condensed with other rings, with one nitrogen atom as the only ring hetero atom and three or more double bonds between ring members or between ring members and non-ring members having three double bonds between ring members or between ring members and non-ring members
- C07D213/89—Heterocyclic compounds containing six-membered rings, not condensed with other rings, with one nitrogen atom as the only ring hetero atom and three or more double bonds between ring members or between ring members and non-ring members having three double bonds between ring members or between ring members and non-ring members with hetero atoms directly attached to the ring nitrogen atom
Abstract
ABSTRACT OF THE DISCLOSURE
An improved integrated route to bis-(2-pyridyl-1-oxide) disulfide is provided by oxidizing 2-chloropyridine with permaleic acid to form 2-chloropyridine-1-oxide followed by mercaptization with a selected alkali metal sulfide to form the alkali metal salt of 2-mercaptopyridine-1-oxide and then oxidation with hydrogen peroxide under selected pH conditions.
An improved integrated route to bis-(2-pyridyl-1-oxide) disulfide is provided by oxidizing 2-chloropyridine with permaleic acid to form 2-chloropyridine-1-oxide followed by mercaptization with a selected alkali metal sulfide to form the alkali metal salt of 2-mercaptopyridine-1-oxide and then oxidation with hydrogen peroxide under selected pH conditions.
Description
~ 5'~7~ C-6324 This invention relates to an improved, integrated method - for preparing bis-(2-pyridyl-1-oxide) disulfide in high purity and high yield. More particularly, this invention involves the preparation of the aforesaid disulfide compound in an integrated, in-situ method by oxid-izing the alkali metal salt of 2-mercapto-pyridine, which i~ obtained by oxidation of 2-chloropyridine with ^~ permaleic acid followed by mercaptlzation with a selected sulfide, wlth hydrogen peroxide using selected pH conditions.
~ The preparation of bis-~2-pyridyl-1-oxide) disulfide (also - 10 referred to a~ 2,2'-dithiodipyridine-l,l'dioxide) hereinafter referred to as the disulfide, has been previouæly broadly disclosed in U.S. Patent 2,742,476 wherein mercaptopyridine-l-oxide is reacted with an oxidizing agent. U.S. Paten~ 3,759,932 also generally discloses the preparation of a disulfide componnd using an in-situ prepsration technique wherein mercaptopyridine is - not isolated. While these references broadly disclose the pre-para~ion of the disulfide, problems have arisen when using the alkali metal salt of 2-mercaptopyridine-1-oxide in an in-situ technique wherein the alkali metal salt was obtained by oxidizing
~ The preparation of bis-~2-pyridyl-1-oxide) disulfide (also - 10 referred to a~ 2,2'-dithiodipyridine-l,l'dioxide) hereinafter referred to as the disulfide, has been previouæly broadly disclosed in U.S. Patent 2,742,476 wherein mercaptopyridine-l-oxide is reacted with an oxidizing agent. U.S. Paten~ 3,759,932 also generally discloses the preparation of a disulfide componnd using an in-situ prepsration technique wherein mercaptopyridine is - not isolated. While these references broadly disclose the pre-para~ion of the disulfide, problems have arisen when using the alkali metal salt of 2-mercaptopyridine-1-oxide in an in-situ technique wherein the alkali metal salt was obtained by oxidizing
2-chloropyridine with permaleic acid to form ~he N-oxide followed by mercaptization to form the ~alt. When using ~h~s system, oxidation by the known techn~ques as shown for example in U.S.
Patent 2,742,476 resulted in the formation of undeslred by-products such as the alk~li metal maleate and al~ali metal fumarate.
This contaminated the desired disulfide product and lowered the yield. ' ;
It has now bee~ found that when using permaleic acid in the preparatlon of 2-chloropyridine-1-oxide during the integrated preparation of the disulfide, the above noted by-product formation can be avoided and surpri~ingly high yields obtained by operating . .
- 2 - ~ ~
~5,~7~ C-632~ .
the final oxidation in the presence of hydrogen peroxide at ~elected pH condi~ions~ More particularly the oxidation of the alkali metal salt of 2-mer aptopyridine-l-oxide i8 carried out at a pH of about 4 to about 5 and preferably from about 4.5 to about 5. The overall reaction scheme of thts invention i~
illustrated by the following e~uation:
~ . .
~ permaleic acid~ ~ NaSEI ~ ~
~ NJCl ~p~~ N/lSNa :
~:1s s ~ ~
In the reaction of this invention as illustrated above, 2-chloropyridlne i8 oxidized to ~he N-oxide using permaleic acid .
in accordance with known procedures as dlsclosed for example in U.S. Patent 2,951,844. The mercaptization of the 2-chloropyridine N-oxide i8 carried out using an alkali metal sulfide or alkali metal hydrosulfide in accordance with known procedures as di~closed in U.S. Patent 2,686,786. The key ~tep in this invention is the oxidation of the prepared alkali metal salt of 2-mercaptopyridine-l-oxide u~ing hydrogen peroxide and a reac~ion pH of about 4 to about 5. By maintaining thë reaction under the6e conditions, the precipitatlon of undesired impuritle~, primarily derived from the salts of fumaric acid is avoided and surprisingly high yields resulted.
In carrying out the reactlon of this invention, the temperature ,.
~z79z C-632~
may generally be maintained from about 15 to about 35C. ~7ith about 20 to abo~t 30~C. being preferred. The hydrogen peroxide concentration may be varied with about 5 to about 30~ in aqueous solution being generally used. Generally a stoich~ometric ratio of the alkali metal salt of 2-mercaptopyridine and hydrogen peroxide of about 2 moles of the mercaptopyridine salt to about 1 mole of peroxide or a ~light excess of up to about 15% peroxide is used.
It is also generally advisable to agitate the reaction mixture in the peroxide oxidation step to maintain an effectively dilute hydrogen peroxide solution.
The pH Df the reac~ion mixture is generally adjusted before the peroxide oxidation step by using any suitable acidifying agent such as the non-oxidizing mineral acids such as HCl and the non-oxidizing organic acids.
While 2-chloropyridine has been shown to be a desired starting material in the method of this inven~ion, other 2-halopyridines and substituted halopyridines containing groups such as lower alkyl and lower alkoxy which do not adversely affect the reaction may also be used. ~ -Isolation of the final product after oxidation is obtained by a standard filtration procedure. ;' The disulfied compounds prepared in accordance with the method of this invention have a variety oE known uses, particularly as antibacterial and antifungal agents in a variety of applications such as ~o combat agricultural plant diseases ~nd in plastics and fabrlcs to resist mildew or other fungus a~tack as disclosed in U.S. Patent 2,742,476.
The following examples are further illustrative of this invention.
, ' ,., ;~:
.. . . .
C-632~
` l~S~79~
Example I
A 2-liter, 3-neck flask fitted with a stirrer, thermometer and addition funnel wa6 charged with 1~866 ~ of 8 reaction mixture containing the sodium salt of 2-mercaptopyridine-1-oxide. This reaction mixture had an assay of 7.2% (135 8) of the sodium salt o 2-mercaptopyridine-1-oxide, 7% sodium chloride and 13-14% total of sodium maleate and sodium fumarate. Thls mixture was obtained by oxidi~ing 2-chloropyridine with permaleic acid and then mercapti-zing wlth NaSH. The pH was then ad~usted to 4.5 with concentrated hydrochloric acid and the resulting warm solution was cooled to 25C. and 52 ml. of 30% hydrogen peroxide (12% excess over stoichiometry) in 160 ml. water added dropwise over a 30 mlnute period with stirring. The reaction was sligh~ly exothermic with . ,.
the temperature rising to approximately 30C. at the end of the ~-peroxide addition. Stirring of the now precipitated bis-(2-pyridyl-l-oxide) disulfide product was continued for 2 more hours to assure completeness of the reaction. The disulfide product for~ed was collected by filtration and the filter cake washed with 50 ml. water followed by 50 ml of methanol. After air drying, a total of 112 g (98% yield based on starting sodium salt of 2-mercaptopyridine-1-oxide) of bis-(2-pyridyl-1-oxide) disulfide . .
was obtained with a melting point of 200-201C. and an assay of , .
8%.
.~ .
Example II
Using th~ same procedure as Example I with a reaction "
mlxture containlng 25.6 g of the sodium salt of 2-mercap~opyridine-l-oxide 9 14 g of 10% hydrogen peroxide, a pH of 4.0 and a reaction time of 18 hour~, 17.0 g of the disulfide product was obtained (79.8% yield ba6ed on sodium salt) having as assay of 97.8%.
. ' ,'': ~ ' .
~ .
.
j, . ;
.: : : .
~ ~S'~7 ~f~ C-6324 Example III
Using the same procedure as Example I with a reaction mixture containing 25.6 g of the sodium salt of 2-mercaptopyridine-1-oxide, 14 g of 10% hydrogen peroxide, a pH of 5.0, a reaction temperature of 20 ~o 23C. and a reaction time of 18 hours, 19.0 g of the disulfide product was obtained ~89.3% yield based on sodium salt) and an a~say of 97~7%.
Example IV .
For comparative purposes, the same procedure as Example II
10was followed with a pH of 3Ø A product of 23.5 g was obtalned, .`.
however, it was contaminated with significant quantities of furmaric acid impurlties.
Example V
For comparative purposes, the same procuedure a3 Example III ~.-was followed with a p~ of 5.5 and a reaction time of 72 hours. A
product of 10.5 g (b9.3% yield) was obtained. ; ~.
';
, - 6 -.
Patent 2,742,476 resulted in the formation of undeslred by-products such as the alk~li metal maleate and al~ali metal fumarate.
This contaminated the desired disulfide product and lowered the yield. ' ;
It has now bee~ found that when using permaleic acid in the preparatlon of 2-chloropyridine-1-oxide during the integrated preparation of the disulfide, the above noted by-product formation can be avoided and surpri~ingly high yields obtained by operating . .
- 2 - ~ ~
~5,~7~ C-632~ .
the final oxidation in the presence of hydrogen peroxide at ~elected pH condi~ions~ More particularly the oxidation of the alkali metal salt of 2-mer aptopyridine-l-oxide i8 carried out at a pH of about 4 to about 5 and preferably from about 4.5 to about 5. The overall reaction scheme of thts invention i~
illustrated by the following e~uation:
~ . .
~ permaleic acid~ ~ NaSEI ~ ~
~ NJCl ~p~~ N/lSNa :
~:1s s ~ ~
In the reaction of this invention as illustrated above, 2-chloropyridlne i8 oxidized to ~he N-oxide using permaleic acid .
in accordance with known procedures as dlsclosed for example in U.S. Patent 2,951,844. The mercaptization of the 2-chloropyridine N-oxide i8 carried out using an alkali metal sulfide or alkali metal hydrosulfide in accordance with known procedures as di~closed in U.S. Patent 2,686,786. The key ~tep in this invention is the oxidation of the prepared alkali metal salt of 2-mercaptopyridine-l-oxide u~ing hydrogen peroxide and a reac~ion pH of about 4 to about 5. By maintaining thë reaction under the6e conditions, the precipitatlon of undesired impuritle~, primarily derived from the salts of fumaric acid is avoided and surprisingly high yields resulted.
In carrying out the reactlon of this invention, the temperature ,.
~z79z C-632~
may generally be maintained from about 15 to about 35C. ~7ith about 20 to abo~t 30~C. being preferred. The hydrogen peroxide concentration may be varied with about 5 to about 30~ in aqueous solution being generally used. Generally a stoich~ometric ratio of the alkali metal salt of 2-mercaptopyridine and hydrogen peroxide of about 2 moles of the mercaptopyridine salt to about 1 mole of peroxide or a ~light excess of up to about 15% peroxide is used.
It is also generally advisable to agitate the reaction mixture in the peroxide oxidation step to maintain an effectively dilute hydrogen peroxide solution.
The pH Df the reac~ion mixture is generally adjusted before the peroxide oxidation step by using any suitable acidifying agent such as the non-oxidizing mineral acids such as HCl and the non-oxidizing organic acids.
While 2-chloropyridine has been shown to be a desired starting material in the method of this inven~ion, other 2-halopyridines and substituted halopyridines containing groups such as lower alkyl and lower alkoxy which do not adversely affect the reaction may also be used. ~ -Isolation of the final product after oxidation is obtained by a standard filtration procedure. ;' The disulfied compounds prepared in accordance with the method of this invention have a variety oE known uses, particularly as antibacterial and antifungal agents in a variety of applications such as ~o combat agricultural plant diseases ~nd in plastics and fabrlcs to resist mildew or other fungus a~tack as disclosed in U.S. Patent 2,742,476.
The following examples are further illustrative of this invention.
, ' ,., ;~:
.. . . .
C-632~
` l~S~79~
Example I
A 2-liter, 3-neck flask fitted with a stirrer, thermometer and addition funnel wa6 charged with 1~866 ~ of 8 reaction mixture containing the sodium salt of 2-mercaptopyridine-1-oxide. This reaction mixture had an assay of 7.2% (135 8) of the sodium salt o 2-mercaptopyridine-1-oxide, 7% sodium chloride and 13-14% total of sodium maleate and sodium fumarate. Thls mixture was obtained by oxidi~ing 2-chloropyridine with permaleic acid and then mercapti-zing wlth NaSH. The pH was then ad~usted to 4.5 with concentrated hydrochloric acid and the resulting warm solution was cooled to 25C. and 52 ml. of 30% hydrogen peroxide (12% excess over stoichiometry) in 160 ml. water added dropwise over a 30 mlnute period with stirring. The reaction was sligh~ly exothermic with . ,.
the temperature rising to approximately 30C. at the end of the ~-peroxide addition. Stirring of the now precipitated bis-(2-pyridyl-l-oxide) disulfide product was continued for 2 more hours to assure completeness of the reaction. The disulfide product for~ed was collected by filtration and the filter cake washed with 50 ml. water followed by 50 ml of methanol. After air drying, a total of 112 g (98% yield based on starting sodium salt of 2-mercaptopyridine-1-oxide) of bis-(2-pyridyl-1-oxide) disulfide . .
was obtained with a melting point of 200-201C. and an assay of , .
8%.
.~ .
Example II
Using th~ same procedure as Example I with a reaction "
mlxture containlng 25.6 g of the sodium salt of 2-mercap~opyridine-l-oxide 9 14 g of 10% hydrogen peroxide, a pH of 4.0 and a reaction time of 18 hour~, 17.0 g of the disulfide product was obtained (79.8% yield ba6ed on sodium salt) having as assay of 97.8%.
. ' ,'': ~ ' .
~ .
.
j, . ;
.: : : .
~ ~S'~7 ~f~ C-6324 Example III
Using the same procedure as Example I with a reaction mixture containing 25.6 g of the sodium salt of 2-mercaptopyridine-1-oxide, 14 g of 10% hydrogen peroxide, a pH of 5.0, a reaction temperature of 20 ~o 23C. and a reaction time of 18 hours, 19.0 g of the disulfide product was obtained ~89.3% yield based on sodium salt) and an a~say of 97~7%.
Example IV .
For comparative purposes, the same procedure as Example II
10was followed with a pH of 3Ø A product of 23.5 g was obtalned, .`.
however, it was contaminated with significant quantities of furmaric acid impurlties.
Example V
For comparative purposes, the same procuedure a3 Example III ~.-was followed with a p~ of 5.5 and a reaction time of 72 hours. A
product of 10.5 g (b9.3% yield) was obtained. ; ~.
';
, - 6 -.
Claims (8)
1. In the method of preparing bis-(2-pyridyl-1-oxide) disulfide wherein 2-chloropyridine is oxidized with permaleic acid to form a reaction mixture containing 2-chloropyridine-1-oxide which is mercaptized using an alkali metal sulfide or alkali metal hydrosulfide to form the alkali metal salt of 2-mercaptopyridine-1-oxide in solution, the improvement comprising adjusting the pH of the resulting solution to a pH of about 4 to about 5 and then oxidizing with hydrogen peroxide to form the bis-(2-pyridyl-1-oxide) disulfide compound.
2. The method of claim 1 wherein said alkali metal is sodium.
3. The method of claim 2 wherein a pH of about 4.5 to about 5 is used.
4. The method of claim 2 wherein said hydrogen peroxide oxidation is carried out at a temperature of from about 15 to about 35°C.
5. The method of claim 4 wherein a hydrogen peroxide con-centration of from about 5 to about 30% in aqueous solution is used.
6. The method of claim 5 wherein said resulting solution contains sodium fumarate and sodium maleate in addition to the sodium salt of 2-mercaptopyridine-1-oxide.
7. The method of claim 5 wherein a pH of about 4.5 to about 5 is used.
8. The method of claim 7 wherein a temperature of from about 20 to about 30°C. is used.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US466328A US3892760A (en) | 1974-05-02 | 1974-05-02 | Bis-(2-pyridyl-1-oxide) disulfide |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1052792A true CA1052792A (en) | 1979-04-17 |
Family
ID=23851343
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA223,892A Expired CA1052792A (en) | 1974-05-02 | 1975-04-04 | Method for preparing bis-(2-pyridyl-1-oxide) disulfide |
Country Status (17)
| Country | Link |
|---|---|
| US (1) | US3892760A (en) |
| JP (1) | JPS5421344B2 (en) |
| AR (1) | AR208546A1 (en) |
| BE (1) | BE828695A (en) |
| BR (1) | BR7502591A (en) |
| CA (1) | CA1052792A (en) |
| CH (1) | CH597190A5 (en) |
| DK (1) | DK143650C (en) |
| FI (1) | FI58917C (en) |
| FR (1) | FR2269525B1 (en) |
| GB (1) | GB1469907A (en) |
| IE (1) | IE41103B1 (en) |
| IL (1) | IL46996A (en) |
| IT (1) | IT1035419B (en) |
| NL (1) | NL7504696A (en) |
| SE (1) | SE401508B (en) |
| ZA (1) | ZA752024B (en) |
Families Citing this family (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4585871A (en) * | 1982-03-26 | 1986-04-29 | Olin Corporation | Process for oxidizing halopyridines to halopyridine-N-oxides |
| US4504667A (en) * | 1983-06-24 | 1985-03-12 | Olin Corporation | Process for oxidizing halopyridines to halopyridine-N-oxides |
| JP2002265310A (en) * | 2001-03-06 | 2002-09-18 | Nagase Chemtex Corp | Antimicrobial agent composition |
| US6664280B2 (en) | 2001-07-25 | 2003-12-16 | The United States Of America As Represented By The Secretary Of The Army | Antivesicant compounds and methods of making and using thereof |
Family Cites Families (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US2686786A (en) * | 1953-01-09 | 1954-08-17 | Olin Mathieson | Nu-hydroxy-2-pyridinethiones and method of preparing same |
| US2742476A (en) * | 1953-10-26 | 1956-04-17 | Olin Mathieson | Derivatives of 2-mercaptopyridine 1-oxide |
| DE1224744B (en) * | 1956-04-13 | 1966-09-15 | Olin Mathieson | Process for the preparation of bactericidal and fungicidal sulfur-containing pyridine compounds |
| US2951844A (en) * | 1958-11-05 | 1960-09-06 | Olin Mathieson | Cyclic process for manufacture of 2-chloropyridine-1-oxide |
| US3759932A (en) * | 1972-08-25 | 1973-09-18 | Olin Corp | Method for preparing mercaptopyridines using alkali metal polysulfides |
-
1974
- 1974-05-02 US US466328A patent/US3892760A/en not_active Expired - Lifetime
-
1975
- 1975-04-01 IL IL46996A patent/IL46996A/en unknown
- 1975-04-01 ZA ZA00752024A patent/ZA752024B/en unknown
- 1975-04-02 IE IE716/75A patent/IE41103B1/en unknown
- 1975-04-04 CA CA223,892A patent/CA1052792A/en not_active Expired
- 1975-04-08 GB GB1439675A patent/GB1469907A/en not_active Expired
- 1975-04-18 DK DK168275A patent/DK143650C/en not_active IP Right Cessation
- 1975-04-21 NL NL7504696A patent/NL7504696A/en not_active Application Discontinuation
- 1975-04-22 IT IT49240/75A patent/IT1035419B/en active
- 1975-04-25 FI FI751253A patent/FI58917C/en not_active IP Right Cessation
- 1975-04-29 BR BR3288/75D patent/BR7502591A/en unknown
- 1975-04-30 CH CH554575A patent/CH597190A5/xx not_active IP Right Cessation
- 1975-04-30 FR FR7513649A patent/FR2269525B1/fr not_active Expired
- 1975-05-01 JP JP5307175A patent/JPS5421344B2/ja not_active Expired
- 1975-05-02 BE BE156038A patent/BE828695A/en unknown
- 1975-05-02 SE SE7505136A patent/SE401508B/en unknown
-
1977
- 1977-02-15 AR AR20854677D patent/AR208546A1/en active
Also Published As
| Publication number | Publication date |
|---|---|
| FR2269525A1 (en) | 1975-11-28 |
| ZA752024B (en) | 1976-02-25 |
| BE828695A (en) | 1975-11-03 |
| AU7996875A (en) | 1976-10-14 |
| JPS50149680A (en) | 1975-11-29 |
| SE401508B (en) | 1978-05-16 |
| CH597190A5 (en) | 1978-03-31 |
| IE41103B1 (en) | 1979-10-24 |
| US3892760A (en) | 1975-07-01 |
| IL46996A (en) | 1977-12-30 |
| BR7502591A (en) | 1976-03-16 |
| DK143650B (en) | 1981-09-21 |
| FI751253A (en) | 1975-11-03 |
| JPS5421344B2 (en) | 1979-07-30 |
| FI58917C (en) | 1981-05-11 |
| IT1035419B (en) | 1979-10-20 |
| IE41103L (en) | 1975-11-02 |
| NL7504696A (en) | 1975-11-04 |
| DK143650C (en) | 1982-02-15 |
| FI58917B (en) | 1981-01-30 |
| IL46996A0 (en) | 1975-06-25 |
| DE2519715B2 (en) | 1977-03-31 |
| DE2519715A1 (en) | 1975-11-06 |
| AR208546A1 (en) | 1977-02-15 |
| GB1469907A (en) | 1977-04-06 |
| FR2269525B1 (en) | 1979-10-05 |
| DK168275A (en) | 1975-11-03 |
| SE7505136L (en) | 1975-11-03 |
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