DK143650B - Process for the preparation of bis- (2-pyridyl-1-oxide) disulfide - Google Patents
Process for the preparation of bis- (2-pyridyl-1-oxide) disulfide Download PDFInfo
- Publication number
- DK143650B DK143650B DK168275AA DK168275A DK143650B DK 143650 B DK143650 B DK 143650B DK 168275A A DK168275A A DK 168275AA DK 168275 A DK168275 A DK 168275A DK 143650 B DK143650 B DK 143650B
- Authority
- DK
- Denmark
- Prior art keywords
- oxide
- disulfide
- preparation
- pyridyl
- bis
- Prior art date
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
Landscapes
- Chemical & Material Sciences (AREA)
- Organic Chemistry (AREA)
- Pyridine Compounds (AREA)
- Cosmetics (AREA)
Description
i 143650 oi 143650 o
Den foreliggende opfindelse angår en særlig fremgangsmåde til fremstilling af bis-(2-pyridyl-l-oxid)-disulfid, hvorved denne fornindelse fås med høj renhed og i stort udbytte .The present invention relates to a particular process for the preparation of bis (2-pyridyl-1-oxide) disulfide, whereby this compound is obtained with high purity and in high yield.
5 Fremgangsmåden ifølge opfindelsen er af den art, hvor en 2-halogenpyridin oxideres med permaleinsyre til dannelse af en reaktionsblanding indeholdende 2-halogenpyridin-l-oxid, som mercaptiseres under anvendelse af et alkalimetalsulfid eller alkalimetalhydrogensulfid til dannelse af alkalimetalsaltet 10 af 2-mercaptopyridin-l-oxid i opløsning, hvorefter der foretages en oxidation med hydrogenperoxid til dannelse af bis-(2--pyridyl-l-oxid).-disulfid, som isoleres, og den er ifølge opfindelsen ejendommelig ved, at oxidationen med hydrogenperoxid foretages ved en pH-værdi på 4-5 og ved en temperatur på 15 15-35°C.The process of the invention is of the kind in which a 2-halo pyridine is oxidized with permaleic acid to form a reaction mixture containing 2-halo pyridine 1-oxide which is mercaptized using an alkali metal sulfide or alkali metal hydrogen sulfide to form the alkali metal salt of 10 1-oxide in solution, after which an oxidation is made with hydrogen peroxide to form bis- (2-pyridyl-1-oxide) disulfide, which is isolated, and according to the invention is characterized by the oxidation with hydrogen peroxide pH value of 4-5 and at a temperature of 15 15-35 ° C.
Fremstillingen af bis-(2-pyridyl-l-oxid)-disulfid (også benævnt 2,2'-dithiodipyridin-1,1'-dioxid), i det følgende kaldet disulfid, er bredt beskrevet i USA-patentskrift nr. 2.742.476, ifølge hvilket mercaptopyridin-l-oxid omsættes med 20 et oxidationsmiddel. I USA-patentskrift nr. 3.759.932 er ligeledes bredt beskrevet fremstillingen af en disulfidforbindelse under anvendelse af en in-situ fremstillingsmetode, hvor mer-captopyridin ikke isoleres. Selv om disse patentskrifter i store træk beskriver fremstillingen af disulfid, er der opstået 25 problemer ved anvendelse af alkalimetalsaltet af 2-mercaptopyridin-l-oxid i en in-situ fremgangsmåde, hvor alkalimetalsaltet fås ved oxidation af 2-halogenpyridin med permaleinsyre til dannelse af N-oxidet og derpå følgende mercaptisering af dette, idet oxidation på kendt måde, som f.eks. beskrevet i 30 USA-patentskrift nr. 2.742.476, da vil resultere i dannelse af uønskede biprodukter såsom alkalimetalmaleat og alkalimetalfu-marat, der forurener det ønskede disulfidprodukt og nedsætter udbyttet.The preparation of bis- (2-pyridyl-1-oxide) disulfide (also referred to as 2,2'-dithiodipyridine-1,1'-dioxide), hereinafter called disulfide, is widely described in U.S. Patent No. 2,742. 476, according to which mercaptopyridine-1-oxide is reacted with an oxidizing agent. U.S. Patent No. 3,759,932 also broadly describes the preparation of a disulfide compound using an in situ preparation method in which mer-captopyridine is not isolated. Although these patents broadly describe the preparation of disulfide, 25 problems have been encountered using the alkali metal salt of 2-mercaptopyridine-1-oxide in an in situ process where the alkali metal salt is obtained by oxidation of 2-halogenopyridine with permaleic acid to form The N-oxide and subsequent mercaptization thereof, with oxidation in known manner, e.g. disclosed in U.S. Patent No. 2,742,476 will then result in the formation of undesirable by-products such as alkali metal maleate and alkali metal phosphate which contaminate the desired disulfide product and decrease the yield.
Det har nu vist sig, at når der anvendes permaleinsyre 35 til den fremstilling af 2-chlorpyridin-l-oxid, som indgår i den samlede fremgangsmåde til fremstilling af disulfid, kan 143650 2 0 man undgå ovennævnte dannelse af biprodukter og opnå overraskende høje udbytter ved at foretage slutoxidationen med hy-drogenperoxid ved en pH-vaerdi på 4-5, fortrinsvis 4,5-5, og ved en temperatur på 15-35°C. Det samlede reaktionsskema for 5 fremgangsmåden ifølge opfindelsen illustreres ved følgende reaktionsskema: „-> /V JisSL^ j permalemsyre x | | 10 Cl Cl SNaIt has now been found that when permaleic acid 35 is used for the preparation of 2-chloropyridine-1-oxide which is part of the overall process for the preparation of disulfide, the above-mentioned by-product formation can be avoided and surprisingly high yields can be obtained. by conducting the final oxidation with hydrogen peroxide at a pH of 4-5, preferably 4.5-5, and at a temperature of 15-35 ° C. The overall reaction scheme for the process of the invention is illustrated by the following reaction scheme: "-> / V JisSL ^ j permalactic acid x | | 10 Cl Cl SNa
Ψ IΨ I
O OISLAND ISLAND
/ H2°2 Ψ pH 4-5 „ Π ί^ι ψ 'Å// H2 ° 2 Ψ pH 4-5 "Π ί ^ ι ψ 'Å /
o OIsland Island
Ved den ovenfor viste omsætning oxideres 2-chlorpyri-20 din til N-oxidet under anvendelse af permaleinsyre på kendt måde som f.eks. beskrevet i USA-patentskrift nr. 2.951.844. Mercaptiseringen af 2-chlorpyridin-N-oxidet udføres under anvendelse af et alkalimetalsulfid eller alkalimetalhydrogen-sulfid på kendt måde som beskrevet i USA-patentskrift nr.In the reaction shown above, 2-chloropyridine is oxidized to the N-oxide using permaleic acid in a known manner, e.g. disclosed in U.S. Patent No. 2,951,844. The mercaptization of the 2-chloropyridine N-oxide is carried out using an alkali metal sulfide or alkali metal hydrogen sulfide in a known manner as described in U.S. Pat.
25 2.686.786. Det essentielle for fremgangsmåden ifølge opfindel sen er, at oxidationen af alkalimetalsaltet af 2-mercaptopyri-din-l-oxid med hydrogenperoxid udføres ved en pH-værdi på 4-5 og ved en temperatur på 15-35°C, idet der under disse betingelser undgås dannelse af uønskede urenheder, som primært er 30 afledt af saltene af fumarsyre, og opnås overraskende høje udbytter.25, 2,686,786. Essential to the process of the invention is that the oxidation of the alkali metal salt of 2-mercaptopyridine-1-oxide with hydrogen peroxide is carried out at a pH of 4-5 and at a temperature of 15-35 ° C, conditions, the formation of undesirable impurities which are primarily derived from the salts of fumaric acid is avoided and surprisingly high yields are obtained.
Ved udførelsen af oxidationen med hydrogenperoxid holdes temperaturen fortrinsvis på mellem ca. 20 og ca. 30°C. Hy-drogenperoxidkoncentrationen kan varieres fra ca. 5 til ca.In conducting the oxidation with hydrogen peroxide, the temperature is preferably maintained between 20 and approx. 30 ° C. The hydrogen peroxide concentration can be varied from ca. 5 to approx.
35 30% i gængs vandig opløsning. Sædvanligvis anvendes der et stø kiometrisk forhold mellem alkalimetalsaltet af 2-mercaptopyri- 0 3 143650 din og hydrogenperoxid på ca. 2 mol mercaptopyridinsalt til ca. 1 mol peroxid eller et lille overskud af peroxid på op til ca. 15%.35 30% in common aqueous solution. Generally, a stoichiometric ratio of the alkali metal salt of 2-mercaptopyridine to hydrogen peroxide of approx. 2 moles of mercaptopyridine salt to approx. 1 mole of peroxide or a small excess of peroxide of up to approx. 15%.
Det er sædvanligvis også tilrådeligt at omrøre reak-5 tionsblandingen i peroxidoxidationstrinnet til opretholdelse af en effektivt fortyndet hydrogenperoxidopløsning.It is usually also advisable to stir the reaction mixture in the peroxide oxidation step to maintain an efficiently diluted hydrogen peroxide solution.
Reaktionsblandingens pH-værdi indstilles, pH indstilles altid før oxidationen før peroxidoxidationstrinnet under anvendelse af et hvilket som helst syrningsmiddel såsom ikke-oxide-10 rende mineralsyrer, som f.eks. HC1 og ikke-oxiderende organiske syrer.The pH of the reaction mixture is adjusted, the pH is always adjusted prior to the oxidation before the peroxide oxidation step using any acidifying agent such as non-oxidizing mineral acids such as e.g. HCl and non-oxidizing organic acids.
En velegnet udgangsforbindelse er 2-chlorpyridin, men der kan også anvendes andre 2-halogenpyridiner og substituerede halogenpyridiner indeholdende grupper, som f.eks. lavere 25 alkyl og alkoxy, der ikke har nogen uheldig virkning på omsætningen.A suitable starting compound is 2-chloropyridine, but other 2-halogenopyridines and substituted halogenopyridines containing groups such as e.g. lower alkyl and alkoxy which have no adverse effect on the reaction.
Isoleringen af slutproduktet efter oxidationen sker ved en standard-filtreringsmetode.The final product is isolated after the oxidation by a standard filtration method.
De disulfid-produkter, der fås ved fremgangsmåden iføl-20 ge opfindelsen, har mange forskellige anvendelsesmuligheder, især som bactericide og fungicide midler til bekæmpelse af sygdomme hos kulturplanter, samt i kunststoffer og tekstiler til bekæmpelse af meldug eller andre svampeangreb som beskrevet i USA-patentskrift nr. 2.742.476.The disulfide products obtained by the process of the invention have many different uses, in particular as bactericidal and fungicidal agents for the control of diseases of cultural plants, as well as in plastics and textiles for the control of mildew or other fungal infestations as described in the United States. U.S. Patent No. 2,742,476.
25 Nedenstående eksempler tjener til nærmere illustrering af fremgangsmåden ifølge opfindelsen.The following examples serve to further illustrate the process of the invention.
Eksempel 1 I en trehalset kolbe på 2 liter forsynet med omrører, 2o termometer og tildrypningstragt anbragtes 1866 g af en reaktionsblanding indeholdende natriumsaltet af 2-mercaptopyridin--1-oxid. Denne reaktionsblanding indeholdt efter analyse 7,2% (135 g) af natriumsaltet af 2-mercaptopyridin-l-oxid, 7% na-triumchlorid og i alt 13-14% natriummaleat og natriumfumarat 25 og var opnået ved oxidation af 2-chlorpyridin med permalein-syre og efterfølgende mercaptisering med NaSH. Blandingens pH-værdi indstilledes på 4,5 med koncentreret saltsyre, og den 0 4 143650 varme opløsning afkøledes til 25°C, hvorpå der i løbet af ca.Example 1 A 1866 g of a reaction mixture containing the sodium salt of 2-mercaptopyridine-1-oxide was placed in a three-liter flask fitted with a stirrer, 2o thermometer and dripping funnel. This reaction mixture after analysis contained 7.2% (135 g) of the sodium salt of 2-mercaptopyridine-1-oxide, 7% sodium chloride and a total of 13-14% sodium maleate and sodium fumarate 25, and was obtained by oxidation of 2-chloropyridine with permaleic acid and subsequent mercaptization with NaSH. The pH of the mixture was adjusted to 4.5 with concentrated hydrochloric acid and the hot solution cooled to 25 ° C, whereupon about
30 minutter dråbevis tilsattes 52 ml 30%'s hydrogenperoxid (et støkiometrisk overskud på 12%) i 160 ml vand under omrøring. Omsætningen var svagt eksoterm, idet temperaturen steg 5 til ca. 30°C ved slutningen af peroxidtilsætningen. Omrøringen af blandingen indeholdende det udfældede bis-(2-pyridyl--1-oxid)-disulfid-produkt fortsattes i 2 timer til sikring af fuldstændig omsætning, hvorefter disulfidproduktet samledes ved filtrering, og filterkagen vaskedes med 50 ml vand 10 efterfulgt af 50 ml methanol, hvilket efter lufttørring gav i alt 112 g (et udbytte på 98%, beregnet på natriumsaltet af 2-mercaptopyridin-l-oxid) bis-(2-pyridyl-l-oxid)-disulfid med smp. 200-201°C og en renhed på 98%.30 minutes dropwise, 52 ml of 30% hydrogen peroxide (a stoichiometric excess of 12%) was added in 160 ml of water with stirring. The reaction was slightly exothermic as the temperature rose 5 to approx. 30 ° C at the end of the peroxide addition. Stirring of the mixture containing the precipitated bis (2-pyridyl-1-oxide) disulfide product was continued for 2 hours to ensure complete reaction, then the disulfide product was collected by filtration and the filter cake was washed with 50 ml of water followed by 50 ml methanol which, after air drying, gave a total of 112 g (a yield of 98%, calculated on the sodium salt of 2-mercaptopyridine-1-oxide) bis- (2-pyridyl-1-oxide) disulfide, m.p. 200-201 ° C and a purity of 98%.
15 Eksempel 2 På samme måde som beskrevet i eksempel 1, men under anvendelse af en reaktionsblanding indeholdende 25,6 g af natriumsaltet af 2-mercaptopyridin-l-oxid, 14 g 10%'s hydrogenperoxid, en pH-værdi på 4,0 og en reaktionstid på 18 timer, 20 er der opnået 17,0 g disulfidprodukt (et udbytte på 79,5%, beregnet på natriumsaltet) med en renhed på 97,8%.Example 2 In the same manner as described in Example 1, but using 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 4.0 and a reaction time of 18 hours, 20 has been obtained 17.0 g of disulfide product (a yield of 79.5%, calculated on the sodium salt) with a purity of 97.8%.
Eksempel 3 På samme måde som beskrevet i eksempel 1, men under an-25 vendelse af en reaktionsblanding indeholdende 25,6 g af natriumsaltet af 2-mercaptopyridin-l-oxid, 14 g 10%'s hydrogenperoxid, en pH-værdi på 5,0, en reaktionstemperatur på 20-23°C og en reaktionstid på 18 timer, er der opnået 19,0 g disulfidprodukt (et udbytte på 89,3%, beregnet på natriumsaltet) med en ren-30 hed på 97,7%.Example 3 In the same manner as described in Example 1, but using 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 20-23 ° C and a reaction time of 18 hours, 19.0 g of disulfide product (a yield of 89.3%, calculated on the sodium salt) is obtained with a purity of 97.7% .
Eksempel 4Example 4
Til sammenligning er eksempel 2 gentaget med en pH-vær-di på 3,0. Der opnåedes herved 23,5 g produkt, som imidlertid 35 var forurenet med betydelige mængder fumarsyre.For comparison, Example 2 is repeated with a pH of 3.0. There were thus obtained 23.5 g of product, which, however, was contaminated with considerable amounts of fumaric acid.
0 5 1436500 5 143650
Eksempel 5Example 5
Til sammenligning er eksempel 3 gentaget med en pH--værdi på 5,5 og en reaktionstid på 72 timer, hvilket gav 10,5 g produkt, dvs. et udbytte på kun 49,3%.For comparison, Example 3 is repeated with a pH of 5.5 and a reaction time of 72 hours to give 10.5 g of product, ie. a yield of only 49.3%.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US466328A US3892760A (en) | 1974-05-02 | 1974-05-02 | Bis-(2-pyridyl-1-oxide) disulfide |
| US46632874 | 1974-05-02 |
Publications (3)
| Publication Number | Publication Date |
|---|---|
| DK168275A DK168275A (en) | 1975-11-03 |
| DK143650B true DK143650B (en) | 1981-09-21 |
| DK143650C DK143650C (en) | 1982-02-15 |
Family
ID=23851343
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| DK168275A DK143650C (en) | 1974-05-02 | 1975-04-18 | Process for the preparation of 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 |
|---|---|
| CH597190A5 (en) | 1978-03-31 |
| DE2519715B2 (en) | 1977-03-31 |
| BR7502591A (en) | 1976-03-16 |
| IE41103L (en) | 1975-11-02 |
| FI58917C (en) | 1981-05-11 |
| SE7505136L (en) | 1975-11-03 |
| IL46996A (en) | 1977-12-30 |
| JPS5421344B2 (en) | 1979-07-30 |
| NL7504696A (en) | 1975-11-04 |
| AU7996875A (en) | 1976-10-14 |
| IL46996A0 (en) | 1975-06-25 |
| CA1052792A (en) | 1979-04-17 |
| DK143650C (en) | 1982-02-15 |
| DE2519715A1 (en) | 1975-11-06 |
| JPS50149680A (en) | 1975-11-29 |
| GB1469907A (en) | 1977-04-06 |
| FI58917B (en) | 1981-01-30 |
| IE41103B1 (en) | 1979-10-24 |
| FR2269525A1 (en) | 1975-11-28 |
| BE828695A (en) | 1975-11-03 |
| FI751253A (en) | 1975-11-03 |
| FR2269525B1 (en) | 1979-10-05 |
| AR208546A1 (en) | 1977-02-15 |
| DK168275A (en) | 1975-11-03 |
| US3892760A (en) | 1975-07-01 |
| IT1035419B (en) | 1979-10-20 |
| ZA752024B (en) | 1976-02-25 |
| SE401508B (en) | 1978-05-16 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US3159640A (en) | Process for preparing 2-mercaptopyridine-nu oxide | |
| US4396766A (en) | Process for producing sodium and zinc pyrithione | |
| JPS597165A (en) | Pyridyl(oxy/thio)phenoxy compound, herbicidal composition and manufacture | |
| CS225835B2 (en) | The production of the alpha,alpha-unsaturated ketones | |
| DK143650B (en) | Process for the preparation of bis- (2-pyridyl-1-oxide) disulfide | |
| US4486358A (en) | Process for producing N-phosphonomethylglycine | |
| JPS6314740A (en) | Conversion of organic hydroxyl compound to halide | |
| JPS6052145B2 (en) | Method for producing 2,3,5,6-tetrachloropyridine and 3,5,6-trichloropyridin-2-ol | |
| US3639413A (en) | (thio- sulfinyl- and sulfonyl) containing pyridine compounds | |
| JPS5933584B2 (en) | Substituted benzylnitrile derivatives | |
| US3462472A (en) | 1,4- and 1,2-bis(substituted sulfonylthiomethyl)cyclohexane | |
| US3927003A (en) | 6-Hydrazino-2,3,5-trihalo-4-alkylthio pyridines | |
| CA1196014A (en) | Process for producing n-phosphonomethylglycine | |
| US3962260A (en) | 6-hydrazino-2,3,5-trihalo-4-alkylthio pyridines and method of preparing same | |
| Hurd et al. | Pyridine Mercurials | |
| US6133447A (en) | Process for the preparation of substituted pyridines | |
| DK165832B (en) | METHOD OF PREPARING 2-CARBOXY-PYRAZINE-4-OXIDES | |
| US5227527A (en) | Process for the preparation of 3'-aminopropyl 2-chloroethyl sulfone semisulfate | |
| US3635994A (en) | Halopyridine sulfenyl- and sulfonylhalides | |
| US5611906A (en) | Preparation of N-allyl compounds | |
| JPH05230026A (en) | Production of 2-chloro-5-methylpyridine derivative | |
| US3732234A (en) | (thio-,sulfinyl-and sulfonyl)containing pyridine compounds | |
| JPH06504053A (en) | Process for producing 4-alkylsulfonyl-1-alkyl-2-chlorobenzene and the compound | |
| US2914555A (en) | 4-alkylphenyl esters of 4-chlorobenzoic acid | |
| JP4894123B2 (en) | Method for producing perfluoroalkylsulfonyl halide |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| B1 | Patent granted (law 1993) | ||
| PBP | Patent lapsed |