DE539784C - Process for the preparation of dyes of the polymethine series - Google Patents

Description

It is known that polymethine dyes can be prepared by allowing orthoformic acid esters or salts of formic acid to act on cyclammonium salts with a reactive methyl group, ie in the n- or y-position to the nitrogen. These two processes lead to polymethine dyes, which can be referred to as symmetric, because in them two identical heterocyclic compounds are linked by a polymethine chain. Asymmetric polymethine dyes, ie those in which two different heterocycles are linked by a polymethine chain, are not accessible by this process.

It has now been found that one can both symmetrical and asymmetrical. Dyes, furthermore, new intermediates can be obtained if one reacts on cyclammonium salts with reactive methyl groups, ie in a- or ^ -position to the nitrogen, or on their methylene bases, compounds of the general formula

H -

in which χ is a monovalent radical or substituents, such as NHo, Cl, O-alkyl, O-acidyl etc., means to act. Such products include: Imido ethers, imido esters, Amidines, imide halides, etc. or their salts. So it succeeds z. B. by condensation of ι moles of the above compounds with 2 moles of a cyclammonium salt or to obtain its methylene base directly symmetrical dyes. By exposure to at least 1 mole of the mentioned body to 1 mole of a cyclammonium salt or its methylene base can, however, under suitable conditions (e.g. in the presence of acids) in the Intermediate products are usually produced and deposited in very good yields, which are capable, optionally in the form of the corresponding methylene bases, with a further moles of cyclammonium salt or its methylene base symmetrical or asymmetrical Form dyes.

The new intermediate products are also to be used for pharmaceutical purposes.

example 1

A mixture of 104 parts of 1, 3, 3-trimethyl-2-methyleneindoline, 180 parts of formimidoethyl ether chlorohydrate, 500 parts of acetic anhydride and 36 parts of glacial acetic acid is increased to 120 with stirring for 20 minutes

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heated to 130 °. The reaction mixture is then mixed with water to decompose the acetic anhydride and salted out with potassium iodide. When it cools, the iodite of the intermediate separates out in very good yield. It is filtered and crystallized from alcohol, which is deposited in yellowish needles from the decomposition point 240-247 ^0th They dissolve fairly easily in water and are very sparingly soluble in benzene and ether. The new product can also be deposited with potassium perchlorate as a perchlorate compound, which crystallizes from alcohol in yellow prisms with a decomposition point of 228 to 229 °. Furthermore, you can also isolate the free base by z. B. makes the reaction mixture alkaline after cooling with dilute sodium hydroxide solution. A reddish-brown precipitate falls out, which soon becomes resinous. If, however, the alkaline reaction mixture is shaken out with ether and it is allowed to evaporate after separation and filtration, the base is obtained in orange-yellow flakes, but these are not very stable.

The following reactions are likely to take place:

CH ₃
1
-C-

CH ₃ OC, H,

= CH ₂

CH ₃

/
HC

N-H

/ \
H Cl

C- C H, 0xCo H-

H H N-H

H ClH

CH ₃
I.
-C-CH ₃ / T

CC = C-NH ₂ H-HO-C ₂ H ₃ -> H H

Cl CH,

Exposure to alkali CH ₃

\ _{/ χ}

Cl CH ₃

C-C

I I

H H

OC ₂ H ₃ NH ₂

(Intermediate product)

CH ₃

CH ₃

• " ^{: L =} CC - Γη COC! Tg

H H

(methylene base corresponding to the intermediate)

If the formimidoether chlorohydro-

drat by the appropriate amounts of formimide chloride, formamidine chlorohydrate, formiminoacetic acid ester, this leads to the same end product. On the other hand, analogous bodies are obtained if the 1, 3, 3-trimethyl-2-methyleneindoline is used replaced by its substitute products.

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Example 2

242 parts of the obtained in Example 1 intermediate product in the form of the free base and 173 parts of i, 3, 3-trimethyl-2-methyleneindoline are heated with 1200 parts of acetic anhydride with stirring to 40 ⁰ and held for 7 hours at a temperature of 40 to 45 ⁰ . Most of the acetic anhydride is then distilled off under a weak vacuum, water is added to the residue and, after filtration, the dye salt is precipitated with hydrochloric acid. After filtering again, washing with dilute hydrochloric acid and drying, the i, 3, 3, 1 ', 3', 3'-hexamethylstreptomonovinylene-2, 2'-indocyanine chloride is obtained in beautiful crystals in good yield.

The dye formation also takes place in other media, for example in alcohol.

Example 3

110 parts of formimidoethyl ether chlorohydrate are slowly added with stirring to a solution, heated to 60 °, of 346 parts of i, 3,3-trimethyl-2-methylenindo-Hn in 1000 parts of acetic anhydride, and dye formation can be observed immediately. The temperature is increased slowly to 95 ⁰ and the reaction is carried out for ¹ ^ hour. After cooling, water is added and the 1, 3, 3, 1 ', 3', 3'-hexamethylstreptomonovinylene - 2, 2 '- indocyanine chloride is isolated as indicated in Example 2.

One arrives at the same dye if one uses the formimidoethyl ether chlorohydrate replaced by formimide chloride, formamidine chlorohydrate, formiminoacetic acid ester, etc.

Example 4

To a solution of 173 parts of 1, 3, 3-trimethyl-2-methyleneindoline in 1000 parts of pyridine are added with stirring 200 parts Formimidoäthylätherchlorhydrat and heated for 15 to 20 hours at 40 to 50 ^0th The deep red colored solution is diluted with water and the 1, 3, 3, 1 ', 3', 3'-hexamethylstreptomonovinylene -2, 2'-indocyanine chloride precipitated with hydrochloric acid.

Example 5

191.51 parts of N-methyl-6-chloro-a-methylendihydrochinolin and 225 parts Formimidoäthylätherchlorhydrat are dissolved in 1400 parts of pyridine with stirring and held for 15 to 20 hours at 40 to 45 ^0th The dye formed is insoluble in pyridine and has therefore separated out when mixed with ammonium chloride. The ι, i'-dimethyl-6,6'-dichloro-streptomonovinylene-2,2'-quinocyanine chloride is isolated by filtering and washing the residue to remove the ammonium chloride.

Example 6

242 parts of the base obtained according to Example 1 are added to 157 parts with stirring N - methyl - α - methylenedihydroquinoline in 1800 parts of acetic anhydride during heated to 40 to 45 ° for a few hours. After most of the acetic anhydride has been distilled off in vacuo, is diluted with water and the asymmetric Salted out dye with potassium chloride.

Recrystallization from alcohol gives the 1, 1 ', 3, 3-tetramethylstreptomonovinylen-2, a'-indochinocyanine chloride in green, shiny needles, the "tannic cotton or silk in bluish-tinted red Dye shades of good fastness. In an analogous manner, the base obtained in Example 1 can be mixed with the methylene bases substituted quinaldines, such as. B. des 6-methyl, 6-chloro, 6-ethoxy, 8-methyl and / Ϊ-naphthochinaldins to similar asymmetric Dyes are condensed.

Example 7 _go

173 parts of 1, 3, 3-trimethyl-2-methyleneindoline and 120 parts Formamidinchlorhydrat are mixed with 600 parts of acetic anhydride and 35 parts of glacial acetic acid and kept during 16 hours under stirring at a temperature of 40 to 45 ^0th After the excess acetane hydride has been decomposed with water, it is salted out with potassium iodide, whereupon after a short time the iodide of the intermediate product obtained in Example 1 precipitates in sharp prisms with good yield.

Example 8

173 parts of 1, 3, 3-trimethyl-2-methyleneindoline and 40 parts Formamidinchlorhydrat are dissolved in 600 parts of acetic anhydride and 35 parts of glacial acetic acid with stirring and held for 16 hours at a temperature of 45 to 50 ^0th After the reaction mass has been decomposed with water, the 1, 3, 3, 1 ', 3', 3'-hexamethylstreptomonovinylene-2, 2'-indocyanine chloride formed is precipitated with hydrochloric acid.

For example, 1 9

173 parts of 1, 3, 3-trimethyl-2-methylene indoline and 35 parts of formimide chloride chlorohydrate are in 600 parts of acetic acid and 30 parts Glacial acetic acid dissolved with stirring and heated to 50 ° for 16 hours. After completion the reaction, the excess acetic anhydride is decomposed with water and that

formed ι, 3, 3, ι ', 3', 3 '"hexamethyl-streptonionovinylen-2, 2'-indocyanine chloride precipitated with hydrochloric acid.

Claims (2)

Patent claims: i. Process for the preparation of polymethine dyes and their intermediates, characterized in that ι moles of a cyclammonium salt containing methyl groups reactive in α- or yS division with nitrogen or its methylene base with ι moles of a compound of the general formula Η —C < in which χ denotes a monovalent aliphatic radical or a substituent or is condensed with their salts and optionally that obtained in this way Intermediate product converted into the corresponding methylene base by treatment with bases and with a further mol an identical or different cyclammonium salt with reactive methyl groups or with its methylene base is condensed. 2. Modification of the method according to claim 1, characterized in that 2 moles of a cyclammonium salt containing methyl groups reactive in the a- or y-position or its free base are reacted with 1 mole of the imides specified in the main claim or with a salt thereof.