DE1921957A1 - Process for the preparation of bipyridinium compounds - Google Patents

Description

Dr. Hans-Heinrich Willrath .., _D _ ₆₂ Wiesbaden, March 7

Dr. Dieter Weber ^{f y l} ' ^yb ' * «* ™ 1 \% _Q

PATENTANWÄLTE Gustav-Freytag-S «« 6e 2 ^

Telegram address: W1LLPATENT Postal check: Frankfurt Main 67 63 Bank: Dresdner Bank AG. Wiesbaden

Account No. 876 807

Drexel Institute of Technology

32nd & Chestnut Streets Philadelphia, Pennsylvania, USA

Process for the production of Bipyridiniumver-

ties

Priority : June 10, 1968 based on U.S. Patent Application 735,576

The invention "relates to a process for the production of Bipyridinium salts]! by reacting ionic cyanides with Pyridinium compounds. The resulting bipyridinium compounds are electron acceptors, the pyridinium salt, which represents one of the starting materials, an alkylpyridinium salt, such as N-methylpyridinium iodide or H-n-dodecylpyridinium bromide, be, or the starting material can be a cyclic pyridinium salζ, such as N-phenylpyridinium chloride, be, .

The invention "is concerned with a method of manufacture von-bipyridinium salts, which are characterized by the viologenkation are. More specifically "the procedure consists in the

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Conversion of alkyl and cyclic pyridinium salts by conversion with gyanids. The following examples serve to further illustrate the invention. .

example 1 Conversion of N-methylpyridinium iodide

2.00 g (9.05 mmol) of ίΤ-methylpyridinium iodide were placed in a 50 ml round bottom flask with a neck of 30 cm length and 12 mm diameter (Eastman), 1.0 g (20 mmol) sodium cyanide (Fisher reagent) and 20 ml of a mixture of acetone and water (3s1 ylum parts) given. The solution was purged with nitrogen and the neck of the flask was connected to a gas-oxygen forced draft burner melted shut. The flask was placed in a steam bath and heated for hours. It was found that after about 5 Minutes developed a characteristic blue color, and the visible spectrum was characteristic of the ΪΓ, ΪΓ -dimethyl-4 »4'-bipyridinium cation. The flask was in tap water cooled, broken up, and 3 ml of concentrated hydrochloric acid was added. The solution was transferred to a 150 ml beaker, and allowed to oxidize in air until the blue color disappeared.

Concentrated ammonium hydroxide was then added until the solution was basic (pH 9). A solution was then added which contained 2.0 g (5.4 mmol) of 4,4'- ^{diaminostilbene-2,2 1} -disulfonic acid (Eastman Purity), dissolved in 50 ml of a 10% ammonium hydroxide solution. A dark blue-green precipitate formed immediately, which was collected, dried under vacuum.

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net and weighed. Yield 0.576g: $ 23. The empirical formula of the 4,4'-diaminostilbene-2,2'-disulfonic acid salt is CipH-j ^ NpC,, H ₁ .NpOgSp. The yield is a minimum because no attempt has been made to recover unreacted N-methylpyridinium salt.

Example 2

conversion v ^ n Η, η-dodecylpyridinium bromide

In a 125 ml Erlenmeyer flask was 5.0 g (15.3 mmol) of N-n-dodeoylpyridinium bromide and added 75 ml of distilled water. The flask was placed in a container with an inert gas atmosphere which contained oxygen-free nitrogen. Then became oxygen-free nitrogen passed through the solution for 5 minutes, to drive out all the oxygen dissolved in it. 2.5 g (51 mmol) of sodium cyanide (Fisher reagent) were then added to this solution added. The flask was shipped, wrapped in Parafilm M. and left for three weeks.

The solution was filtered in a nitrogen atmosphere, and the collected solid was oxidized with a solution, which contained 4.5 iodine dissolved in 100 ml of 95% ethyl alcohol. The resulting solution was passed through an Amberlite IRA-400 ion exchange resin passed with a content of bromide ions and evaporated to dryness. The resulting pesticide was in a mixture of acetonitrile and chloroform in a volume ratio of 3: 1 dissolved and transferred to 500 ml.

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A 10 ml portion was passed through a chromatographic column (1:, 7 cm χ 11 cm) passed the silica gel (28 - 200 mesh, / Fisher Chromatography Unit). Me following Eluting solvents were used?

1.CHCl, -benzene (volume ratio lsi)

2. CHCl ₃ . . .. ■■ -. "■, 5. CHCl, ethyl acetate (volume ratio-Ί s-1).

4. Ethyl acetate _:

5. Ethyl acetate-ethyl alcohol (volume ratio 9s1)

6. Acetone-acetonitrile-ethyl alcohol-water (volume ratio

- 3: 3s3sT);

Elution was continued with each solvent until until nothing more was eluted from the column. The eluting solvent, containing acetone, acetonitrile, ethyl alcohol and water was evaporated to dryness and the resulting product Plague was recrystallized by putting it in a hot tub Mixture of ethyl alcohol and water (volume ratio 9; T) dissolved and ethyl acetate added up to the cloud point. The solution was cooled, the precipitate collected, dried under vacuum and weighed. Yield 0.0419g; $ 42. The yield stops Minimum because no attempt was made to set the amount: at unreacted N-n-dodecylpyridinium bromide, which remained in the mother liquor to determine.

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1- I (I

By 'comparing the infrared spectrum of this compound with the an authentic sample obtained by quaternizing bipyridyl with dodecyl bromide, the product was identified as N, N'-M-n-dodecyl-4 »4'-dipyridinium bromide.

Analysis calculated for C ^ .H

0 8th H 4th N Br .62 .57 9 .95 4th .28 24.41 62 .21 .07 .08 24.29

calculated
found

The reaction product of sodium cyanide and N-n-dodecylpyridinium bromide became known as NjN'-Di-n-dodecyl-A ^ '- bipyridinium cation identified the following considerations. In one experiment, 10 ml of degassed aqueous 0.2m NaCN solution were degassed with 10 ml mixed aqueous O, O52m N-n-dodecylpyridinium bromide solution. A portion was taken from the solution and placed in an ultraviolet absorption cell transferred that was sealed to exclude oxygen. Almost immediately it became a complex one visible absorption spectrum and blue color observed. The intensity of the absorption spectrum increased over time. At the same time, turbidity occurred and a precipitate formed. The precipitate was collected under nitrogen and dissolved in degassed acetonitrile to obtain an absorption spectrum which was essentially identical to the spectrum observed in the original solution »

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m 9 C ·

* S

-t · «I

- 6 Example 3

Conversion of N-phenylpyridinium chloride

Into a 250 ml Erlenmeyer flask was 100 ml of a mixture of acetone and water in a volume ratio of 1: 1 and 5> 0 g (26 mmol) N-phenylpyridinium chloride added. The flask was placed in a container with an inert gas atmosphere containing oxygen-free nitrogen. Then oxygen became P Free nitrogen passed through the solution for 5 minutes in order to free it from the dissolved oxygen. To this solution were then 2.5 g (51 mmol) sodium cyanide (Pisher reagent grade) added. The Erlenmeyer flask was closed with a cork stopper, with Parafilm M (from the Marathon Division of the American Can Co.) sealed and in a nitrogen atmosphere Left to stand for 6 days at room temperature. It was observed that when the sodium cyanide was added, the solution immediately became cloudy and that a dark red pesticide appeared within 5 minutes. After standing, the solution was filtered and collected the solid product.

The collected plague material was added to an alcoholic Oxidized iodine solution (7.0 g of iodine-Pisher-USP in 100 ml of 95% ethyl alcohol). The thus obtained, containing some particulate matter Solution was through a column (2 cm χ 20 cm) with an: ion exchange resin (Amberlite IRA-400, Rohm & Haas, Philadelphia) sent, which had previously been saturated with bromine ions. The insoluble test material was dissolved in a hot mixture of acetonitrile and water (volume ratio 9M) and also sent through the ion exchange column.

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* r «v« »if- t

In order to ensure a complete ion exchange (bromide for iodide or triodide), the solution was once more through sent a fresh ion exchange column. The resulting solution was evaporated to give a solid that was twice recrystallized from a mixture of acetonitrile, water and ethyl acetate became. The solid was dried under vacuum at 100 ° G. Yield 3.81 g, consisting of Ν, Ν'-diphenyl-4,4'-bipyridinium bromide.

The conversion products obtained according to the invention can be used in the following technical fields:

Herbicide,

Dehydrator,
Photographic material,

Bedox indicator,
Oxidizing agent,

Remedies for treating coccidiosis in poultry, determining small amounts of oxygen gas and Catalysts for Aerobic Cyclic Phosphorylation.

Although specific ionic cyanides are used in the above examples it should be noted that other ionic cyanides can also be used when carrying out the process according to the present invention Invention are effective in the same way. For example, the cyanides of the alkali metals or alkaline earth metals can also be used can be used as well as ammonium cyanide and organoammonium cyanide. The examples can be viewed as including the use of such ionic cyanides instead of those in the

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Examples of special cyanides,

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Claims (2)

Claims 1. Process for the preparation of bipyridinium salts from N-methylpyridinium salts and N-phenylpyridinium salts, characterized in that the pyridinium salts are in aqueous Acetone reacts with a cyanide in the absence of oxygen. 2. The method according to claim 1, characterized in that nitrogen is passed through the aqueous acetone and it so freed of oxygen. 909850/1752