DD149216A1 - PROCESS FOR THE PREPARATION OF 2- (OMEGA-CARBOXY-ALKYL) CYCLAMMONIUM SALTS - Google Patents

Abstract

Such compounds are important as intermediates for the synthesis of cyanine dyes. The preparation according to the invention is effected by reacting 2- (2-dialkylamino-cycloalkenyl) cyclammonium salts of the formula 1 or 2-heterocyclicycloalkanones of the formula II in the presence of an organic or inorganic acid to give the 2 - (* - carboxyalkyl) cyclammonium salts of the formula III be implemented.

Description

-A-

Title of the invention

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Process for the preparation of 2- (a> -Carboxy-alkyl) cyclammonium salts

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Field of application of the invention

The invention relates to a process for the preparation of 2 - (<υ-carboxy-alkyl) cyclammonium salts. Such compounds have significance as dye intermediates, in particular for the synthesis of unsymmetriach-substituted in the end groups and bridged cyanine dyes.

Characteristic of the known technical solutions Methods for the preparation of the 2- (w-carboxyalkyl) cyclammonium salts according to the invention have not hitherto been described.

Object of the invention

The aim of the invention is to produce 2- (w-carboxyalkyl) cyclammonium salts from readily available starting materials.

Explanation of the essence of the invention

The object of the invention is to synthesize 2 - ("- carboxyalkyl) cyclammoniuinsalse in a simple manner from readily available starting materials.

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According to the invention, this object is achieved in that a compound of the formula I,

wherein R is an optionally substituted alkyl, aralkyl or aryl group or an alkenyl group; Rg, R ^ are each an alkyl or aryl group or, together with the II atom, the necessary atoms to complete a heterocyclic ring, eg _{# of} a pyrrolidine, piperidine or morpholine ring; Y is oxygen, sulfur, selenium or the groupings -II (alkyl) - or -C (alkyl) p-; ' Z atoms necessary to complete a 5-membered heterocyclic ring which may contain an annelated benzene or naphthalene ring and other substituents and is of the type customary in cyanine chemistry; Σ ^{θ is} any anion such as chloride, bromide, iodide, perchlorate, methylsulfate, p-toluene-3-sulfonate, etc., which is omitted when R _{1 contains} an anionic group such that betaine is present and η is 2, 3 or 4, or one Compound of the formula II,

in which R ₁ , Y, Z and η are as defined above, in the presence of an organic acid such as formic acid, acetic acid

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acid, p-toluenesulfonic acid, etc. or inorganic acid such as perchloric acid, sulfuric acid, phosphoric acid, etc. at a temperature between 50 ⁰ C and 150 ⁰ C is reacted and a 2- (a> -Carboxy-alk7l) cyclammoniuia8alz the formula III,

¹¹¹ 'Z''/ - CH ₂ - (CH ₂ ) -CH _r C00H

Χ ^θ

in which R, Y, Z, X ^e have the meanings given as given,

Aueführungabeispiele

example 1

Preparation of 2- (4-carboxybutyl) -3-methylbenzothiazolium perchlorate

700 mg of 2- (3-methylbenzothiazolin-2-ylidene) cyclopentanone are refluxed in 2 ml of glacial acetic acid for 3 hours. It is precipitated with a 30% strength aqueous sodium perchlorate solution, filtered off with suction and crystallized from glacial acetic acid.

Yield: 67 % d. Th .; F «182 ⁰ C

Example 2

Preparation of 2- (5-carboxypentyl) -3-methylbenzothiazolium perchlorate

25 g 3-methyl-2- (2-morpholino-cyclohex-1-enyl) benzthiazoliumperchlorat are heated in 11 ml of 85 ^ formic acid on a water bath for 3 hours at 90 ⁰ C. It is mixed with a 30% aqueous Natriumpc rorkatlb'sung and allowed for several hours

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Crystallization stand »The product is filtered off, washed with a little water and recrystallized from glacial acetic acid.

Yield: 70 % d. Th .; P * 116 ⁰ C

Example 3

Preparation of 2- (5-carboxypentyl) -3-methylbenzothiazolium perchlorate

6.22 g of 3-methyl-2- (2-morpholino-cyclohex-1-enyl) benzthiazoliumperchlorat be heated in 2.5 g of 60% perchloric acid on a water bath for 5 hours at 90 ⁰ C. The work-up is carried out as indicated in Example 2.

Yield: 47 % d. Th ,; P. 116 ⁰ C

Example 4

Preparation of 2- (5-carboxypentyl) -3-methylbenzothiazolium perchlorate

14.7 g of 2 ~ (3-methyl-benzthiazoline-2-ylidene) cyclohexanone dissolved in 11 ml of 85% formic acid on a water bath heated to 90 ⁰ C for 3 hours. The work-up is carried out as indicated in Example 2.

Yield: 68 % d. Th .; P. 116 ⁰ C

Example 5

Preparation of 2- (6-carboxyhexyl) -3-methylbenzothiazolium perchlorate

261 mg of 2- (3-methylbenzothiazolin-2-ylidene) cycloheptanone are refluxed in 2 ml of glacial acetic acid for 30 minutes. It is precipitated with a 30% aqueous sodium perchlorate solution, filtered off with suction and crystallized from glacial acetic acid.

Yield: 79 % d. Th .; P. 135 ⁰ C

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 Production of the required intermediates

3-methyl-2- (2-morpholino-cyclohex-1-enyl) -benzothiazolium perchlorate

30 g of 3-methyl-2-methylthio-benzthiazolium perchlorate are heated with 32 g of i-morpholino-cyclohex-i-ene in I40 ml of acetic anhydride for 10 minutes under reflux and allowed to stand for several hours at room temperature · rubs with a glass rod, sucks The crystallized 3-methyl-2- (2-morpholino-cydohex - 1-enyl) benzthiazolium perchlorate and washed thoroughly with ether. For purification is recrystallized from methanol. Yield: 53 % d. Th .; P. 195 ⁰ C

2- (3-methyl-benzothiazol-2-ylidene) cyclopentanone

30 g of 3-methyl-2-methylthio-benzthiazolium perchlorate are heated under reflux with 35 g of i-morpholino-cyclopent-1-θη in I40 ml of acetic anhydride for 10 minutes. It is concentrated in vacuo, the residue is dissolved in 12% hydrochloric acid and the ketone falls after a short while with sodium hydroxide solution. It is filtered off with suction and recrystallised from methanol.

Yield: 23 % d. Th .; P. 207 ⁰ C

2- (3-methyl-benzthiazoline-2-ylidene) cyclohexanone

30 g of 3-methyl-2- (2-morpholino-cyclohex-1-enyl) benzthiazolium perchlorate are well powdered in 500 ml of 12% hydrochloric acid. The mixture is heated briefly to 35 ⁰ C and then neutralized with ice cooling with 2N sodium hydroxide solution. The precipitated product is filtered off with suction and dried. For purification, it is dissolved in boiling methanol, slowly cooled to -78 ⁰ C and filtered off with suction. Yield: 50 % ά. Th .; P. 188 ⁰ C

2- (3-methyl-benzthiazoline-2-ylidene) cycloneptanon

6 g of 3-methyl-2-methylthio-benzthiazoliura perchlorate are with

7 g of 1-morpholino-cyclohept-i-ene in 30 ml of acetic anhydride for 10 minutes

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heated under reflux, Daa acetic anhydride is distilled off in vacuo, the residue obtained in 70% perchloric acid dissolved and chromatographed through a column with alumina to BROCKMAM (neutral). The mobile phase used is ethyl acetate. The fraction containing the ketone is concentrated, and the precipitated ketone is filtered off with suction and recrystallised from ethyl acetate.

Yield: 33 % dTh; P _# 111 ⁰ C

Claims (1)

invention claim Process for the preparation of 2- (w-carboxyalkyl) cyclammonium salts of the formula III, Z _ V- ΓΗ - (ΓΗ ) - ΓΗ- III W ^{2 2} R ₁ X ^θ wherein R _{1 represents} an optionally substituted alkyl, aralkyl or aryl group or an alkenyl group; Y is oxygen, sulfur, selenium or the groupings -N (alkyl) - or -C (alkyl) ₂ -; Z atoms necessary to complete a 5-membered heterocyclic ring which may contain a fused benzene or naphthalene ring and further substituents; X ^{θ is} any anion which is omitted when R 1 contains an anionic group and η is 2, 3 or 4, characterized in that a compound of the formula I, wherein R ₁ , Y, Z, X and η are as defined above and R ^, Ro are each an alkyl or aryl group or together with the N atom, the necessary atoms for completion of a heterocyclic ring or a compound of formula II 219 wherein R ₁ , Y, Z and η have the ready indicated meaning, in the presence of an organic or inorganic acid at a temperature between 50 ⁰ C and 150 ⁰ C is reacted.