CS208349B1 - Process for preparing 6-N-acylamino-3-indazolones - Google Patents

Abstract

Method for the production of 6-N-acylamino-3-indazolones β with a free carboxyl group by the reaction of 6-amino-3-indazolone dihydrochloride with succinic acid anhydrides, which are used as a color-forming component for the magenta layer of color photographic material. 6-N-acylamino-3-indazolones of the general formula are produced according to the invention by converting 6-amino-3-indazolone dihydrochloride in acetic acid by the action of its sodium or potassium salt to the free base, which is acylated without isolation with succinic acid anhydrides substituted with an alkyl or alkenyl group with 12 to 18 carbon atoms at a temperature of 60 to 110 °C.

Description

(54) A process for the preparation of 6-N-acylamino-3-indazolones

A process for producing 6-N-acylamino-3-indazolones with a free carboxyl group by reacting 6-amino-3-indazolone dihydrochloride with succinic anhydrides, which is used as a coloring component for the purple layer of color photographic material. According to the invention, the 6-N-acylamino-3-indazolones are prepared by converting 6-amino-3-indazolone dihydrochloride in acetic acid by treatment with its sodium or potassium salt to the free base which is acylated without isolation with succinic anhydrides substituted with an alkyl or alkenyl group of 12 to 18 carbon atoms at a temperature of 60 to 10 ° C.

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SUMMARY OF THE INVENTION It is a process for preparing 6-N-acylamino-3-indazolones with a free carboxyl group by reacting 6-amino-3-indazolone dihydrochloride with succinic anhydrides containing C 12 -C 18 alkyl or alkenyl groups.

N-acylaninoindazolones are color-forming components for the purple layer of color photographic material. For this purpose, acylacyl hydrochlorides of amino-3-indazolones are prepared by the said anhydrides in pyridine at the boiling point of said solvent, which at the same time tows the hydrogen chloride released from the starting hydrochloride. In the case of 6-aminoindazolone, the coloring constituents of formula (I) where R is alkyl or alkenyl containing from 12 to 18 carbon atoms which do not contain a free carboxyl group are formed under the specified conditions and are applied to the photographic emulsion. the ingredients are incorporated into the emulsion in the form of an alkaline solution. In production, the components are isolated from the pyridine solution after reaction by precipitation in dilute hydrochloric acid. Regeneration of fodder from an aqueous solution of its hydrochloride is difficult and economically difficult. Furthermore, the yields of the components after purification of the crude products are generally only about 75% of the theory.

On the other hand, the disadvantages can be eliminated by the preparation of 6-N-acylamino-3-indazolones of the general formula II wherein R is alkyl or alkenyl of 12 to 18 carbon atoms, characterized in that 6-amino-3-indezolone dihydrochloride is converted in acetic acid by its sodium or potassium salts on the free base which, without isolation, acylates succinic anhydrides substituted with an alkyl or alkenyl group of 12 to 18 carbon atoms at a temperature of 60 to 110 ° C. It is preferred to carry out acylcation in a mixture of acetic acid and low boiling aliphatic ketones, preferably acetone.

Example 1

16.6 g of anhydrous sodium acetate are dissolved in 250 ml of glacial acetic acid at 90 DEG C., 22.2 g of 6-amino-3-indazolone dihydrochloride are added in one portion and, after stirring, 34.0 g of hexadecylsuccinic anhydride are added. The mixture is kept under stirring at said temperature for 0.5 h and then cooled to 15-20 ° C. The densely precipitated product was filtered, washed with ethenol, water and dried at 80 ° C. 42.6 g (90% of theory) of the component of formula II (R hexadecyl) are obtained, having a content of 99.8% as determined by the carboxyl group.

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Example 2

27.2 g of crystalline sodium acetate are dissolved in 200 ml of 90% aqueous acetic acid, mixed with 22.2 g of 6-amino-3-indazolone dihydrochloride at 80 DEG C. and 33.8 g of hexadecylsuccinic anhydride are added. After stirring at 100-105 ° C for 40 minutes, the mixture is worked up as in Example 1. 43.4 g (92% of theory) of the component of formula II (R ' hexadecenyl) are obtained with a content of 99.6% by absorbance of the azomethine dye with N , N-diatyl-p-phenylenediamine.

Example 3

30.3 ml of a 29% aqueous potassium hydroxide solution are slowly stirred into 190 ml of glacial acetic acid, 22.2 g of 6-amino-3-indazolone dihydrochloride are added, and the free base solution is treated with 36.8 g of octadecenylsuccinic anhydride as in Example 2. After digesting the component in 200 ml of ethanol, 40 g of coloring component of formula II (R = octadecenyl) are obtained.

Example 4

27.2 g of crystalline sodium acetate are dissolved in 70 ml of acetic acid at 60 DEG C. and the procedure is as in Example 2 except that the anhydride is added dissolved in 100 ml of acetone and acylated for 1 hour with gentle boiling of the mixture. . For isolation, the component is washed with acetone and water. 41 g (86% of theory) of the product of Example 2 are obtained.

Claims (2)

OBJECT OF THE INVENTION A process for the preparation of 6-N-acylamino-3-indazolones having a free carboxyl group of the general formula II wherein R is alkyl or alkenyl of 12 to 18 carbon atoms, characterized in that the 6-amino-3-indazolone dihydrochloride is converted in an acid medium acetic acid by treatment with its sodium or potassium salt on the free base, which is acylated without isolation with amine acid enhydrides substituted with an alkyl or alkenyl group of 12 to 18 carbon atoms, at a temperature of 60 to 110 ° C. 2. The process of claim 1 wherein the acylation is carried out in a mixture of acetic acid and low boiling aliphatic ketones, preferably acetone.