DD285095A5 - PROCESS FOR PREPARING 1-HYDROXY-NAPHTHALENE-2-CARBONSAEUREAMIDE TYPE (2) HYDROXY-ALKYLTHIO-SUBSTITUTED TWO-EQUIVALENT BLUE GREEN COUPPLERS (1) - Google Patents

Abstract

The invention relates to a process for the preparation of 4- (hydroxy-alkylthio) -substituted 1-hydroxy-naphthalene-2-carboxylic acid amide-type two-component-blue-dye couplers which can be used in the photographic industry. According to the invention, * (I) is rearranged by heating in a solvent in the presence of a base to give the naphthalene-2-carboxylic acid amides (II). The crude yields are practically quantitative. After purification by recrystallization they are between 50 and 85 * {* heating; Solvent; Base}

Description

S-

in which R ¹ , R ² and η have the abovementioned meaning, be worked up in a known manner.

Field of application of the invention

The invention relates to a process for the preparation of 4- (hydroxyalkylthio) -substituted two-equivalent cyan couplers of the 1-hydroxy-naphthalene-Z-carboxylic acid amide type which can be used in the photographic industry.

Characteristic of the known state of the art

It is known to prepare cyan couplers of the type of 1-hydroxy-4- (2-hydroxyethylthio) naphthalene-2-carboxylic acid amides by reacting 4-halo-1-hydroxy-naphthalene-2-carboxylic acid amides in the presence of bases with monothioglycol (DD- WP 217 178). This method has the disadvantage that the yields are low. Moreover, working with monothioglycol represents a significant odor nuisance.

Object of the invention

The object of the invention is to produce economically 4- (hydroxy-alkylthio) -substituted 2-equivalent cyan coupler of 1-hydroxynaphthalene-2-carboxylic acid amide type.

Explanation of the essence of the invention

The object of the invention is to develop a process which can be used to prepare 4- (hydroxyalkylthio) -substituted two-equivalent cyan couplers of the i-hydroxy-naphthalene -carboxamide type in a simple manner and starting from readily available starting materials.

This object is achieved in that 1-hydroxy-4- (halo-alkoxycarbonylthio) naphthalene-2-carboxamides of the general formula I,

OH 0

' ^N NH-R ¹

-CO-O- / CH-hal

H ² Jn

in the R ¹ alkyl, aryl, aryloxyalkyl, halogen- and / or alkyl-substituted aryl or Aryloxyalky !. P. '"nleich or differently hydrogen, alkyl or aryl, 2 to 6 Hal is chlorine or bromine and η, at 50-120 ⁰ C in a solvent in the presence of a base is heated for 5-20 minutes and formed 4- (hydroxy alkylthio) -substituted two-equivalent bilayer green couplers of general formula II,

"i

in which R ¹ , R ² and η have the abovementioned meaning, be worked up in a known manner.

I-hydroxy ^ -fhalogeno-alkoxycarbonylthio-naphthalenecarboxylic acid amides which can be used for the process according to the invention,

which are readily known from the unsubstituted in the 4-position compounds and Halogenalkoxycarbonylsulfenylchloriden in known

Make way, z. B .:

1-hydroxy-4- (3-chloro-propoxycarbonylth! O) nephthalen-2-carboxylic acid [4- (2,4-di-tert-amyl-phenoxy) butylamide] 1-hydroxy-4- (4-chloro -butoxycarbonylthio) naphthalene-2-carboxylic acid [4- (2,4-di-tert-ar \ iyl-phenoxy) butylamidl1-hydroxy-4- (2-chloro-ethoxycarbonylthio) naphthalün-2-carbonsäuredodecylamid

Suitable solvents are aprotic, such as dioxane and tetrahydrofuran, or protic, such as methanol, ethenol, propanol and ' Isopropanol used. Preferably, working in ethanol. Suitable bases for the reaction are z. b. Sodium hydroxide, triethylamine or pyridine. The molar ratio of 1-hydroxy-4

(Haloalkoxycarbonylthiolnaphthalene ^ -carboxamide to the base should be 1: 6-12.

The Reaktionstomperatur can be varied within wide limits, advantageously a temperature range of 50-120 ° C, such. B. by the Boiling temperature of the solvent used is specified. It was preferably in boiling ethanol for about 5 minutes

heated. At lower temperatures, the reaction time increases accordingly.

The process according to the invention gives higher yields than those described in the prior art Method. Crude yields are usually virtually quantitative. After purification by recrystallization, they are between 50 and 85Mol-%, usually between 75 and 80 MOI ⁰ A. The compounds can be used as intermediates for dye synthesis or in the photographic industry as Two equivalent cyan couplers are used. embodiments example 1

16.95 g of 1-hydroxy-4- (2-chloro-ethoxycarbonylthio) naphthalenedi-2-carboxylic acid [4- (2,4-di-tert-amyl-phenoxy) -butyl-amide) are dissolved in 135 ml of 2N aqueous sodium hydroxide solution and 70 ml of ethanol for 5 min. Refluxed. The mixture is allowed to cool to about 3O ⁰ C and acidified with 2n HCI. There are precipitated 15.6 g of crude product which is recrystallized from heptane, 12.1 g of a 1-hydroxy-4- (2-hydroxyethylthio) -naphthalene-2-carboxylic acid [4- (2,4-di-tert. -amyl-phenoxy) -butylamide] of melting point 87-90 ° C, which corresponds to a yield of 77%.

Example 2

10 g of 1-hydroxy-4- (3-chloro-propoxycarbonylthio) naphthalene-2-carboxylic acid [4- (2,4-di-tert-amyl-phenoxy) -butyl-amide are analogously to Example 1 with 135 ml of 2N sodium hydroxide solution and 75 ml of methanol Reacted min., Obtaining 9.0 g of crude product which is recrystallized from alcohol, 7.2 g of 1-hydroxy-4- (3-hydroxy-propylthio) naphthalene-2-carboxylic acid (4- (2,4-di-tert. -amyl-phenoxy) -butylamide] of melting point 130-131 ⁰ C, which corresponds to a yield of 77%.

Example 3

10 g of 1-hydroxy-4- (4-chloro-butoxycarbonylthio) naphthalene-2-carboxylic acid (4- (2,4-di-tert-amyl-phenoxy) butylamide] are analogous to Example 1 with 135 ml 2η potassium hydroxide solution and 100 ml of dioxane Reacted to give 7.2 g of crude product which, recrystallized from heptane, 4.6 g of 1-hydroxy-4- (4-hydroxy-butylthio) naphthalene-2-carboxylic acid (4- (2,4-dkert.-amyl- phenoxy) butylamide] of melting point 79-80 ° C, which corresponds to a yield of 49%.

Example 4

10 g of 1-hydroxy-4- (2-chloro-ethoxycarbonylthio) naphthalene-2-carboxylic acid dodecylamide are reacted analogously to Example 1 to give 8.8 g of crude product which, recrystallized from heptane, gives 6.8 g of 1-hydroxy-4- (2 hydroxy-ethylthio) naphthalene-2-carboxylic acid dodecylamide of melting point 60-63 ° C, which corresponds to a yield of 75%.

Claims (1)

A process for the preparation of 4- (hydroxyalkylthio) -substituted two-equivalent cyan couplers of the 1-hydroxy-naphthalene-2-carboxylic acid amide type, characterized in that 1-hydroxy-4- (haloalkoxycarbonylthio) -naphthalene-2-carboxylic acid amides of general formula I, S-CO-O- / CH-hal in which R ^{1 is} alkyl, aryl, aryloxyalkyl, halogen- and / or alkyl-substituted aryl or aryloxyalkyl, R ^{2 is} identical or different, is hydrogen, alkyl or aryl, Hal is chlorine or bromine and η is 2 to 6, at 50-12O ⁰ C. heated in a solvent in the presence of a base for 5-20 minutes and the formed 4- (hydroxy-alkylthio) -substituted two-equivalent cyan couplers of general formula II, OH ₀ I * CTJ NH-R