CS256090B1 - X 2- (2-benzothiazolyl) -1,3-indandiones - Google Patents

Abstract

Yellow, orange and red pigments based on new compounds X-2-(2-benzothiazolyl)-1,3-indanediones of general formula I, X o .co I N where X is H, 4-NO2, 5-NO2, suitable for dyeing PVC, polyethylene, polyester silk, are produced by condensation of phthalic anhydride or its 4-nitro or 3-nitro derivatives with 2-methylbenzothiazole in the presence of a base.

Description

The invention relates to X-2- (2-benzothiazolyl) -1,3-indanediones of the general formula I which, as lived, orange to red pigments, are suitable for dyeing PVC, polyethylene, polyester silk, thermoplastic rubber and the like. and how they are made.

where

X is H, _4-NO2, 5-NO _2nd

The production process is based on the condensation of phthalic anhydride or its 3-nitro, respectively. 4-nitro derivatives with 2-methylbenzothiazole in the presence of a base.

Known in the literature are the pyridine or quinoline derivatives of 1,3-indanedione in the 2-position substituted as color pigments under the name alpha- or gamma-pyrophthalones, respectively. quinaldine yellow or quinophthalone. Said pigments are very suitable for dyeing PVC, polyethylene, polyester silk, polystyrene, methacrylic resins and similar materials and are used in the above sectors of the dyeing industry.

Extensive patent and company literature on phthalones include the following claims: Schefezik E., Ger. Offen 2,132,681; Hunter C., Shellburn US 3,904,420; Nagahama S., Shirmada K., Harada T., Koga M., Japan Kokai 7,847,439; Kerme A., Bundulec M., Bleidelis J., Siepins E., Geterocycle. Soedin. 8, 1076 (1978).

We have now found that 2-methylbenzothiazole is condensed with phthalic anhydride or its 3-NO ₂ or 4-NO ₂ derivatives in an organic base environment such as triethylamine or pyridine at temperatures of about 120-150 ° C and provides a one-off degree of external intensity Rye pigment: 2- (2-benzothiazolyl) -1,3-indanedione and orange-red to red pigments derived from 4-nitro-2- (2-benzothiazolyl) -1,3-indanedione and 5-nitro-2- (2- benzothiazolyl) -1,3-indanedione. They are isolated from the reaction mixture by pouring into water by stirring, separation and drying. The reaction proceeds quantitatively so that the resulting product can be used as a color pigment without purification. The prepared compounds are insoluble in water and in common organic solvents such as ethanol, methanol, acetone, hydrocarbons, chlorinated hydrocarbons. They are poorly soluble in the cold and well heat in dimethylsulfoxide so that they can crystallize from said solvent.

They are compounds which are still, colored, especially when they are eliminated. from an alkaline environment. They can also be used in mixtures with other color pigments to obtain a suitable shade.

The following example illustrates but does not limit the scope of the invention. Example 1

A mixture of remelted phthalic anhydride (respectively a 4-NO ₂ or 3-NO ₂ derivative) (0.1 mol), 2-methylbenzothiazole (0.1 mol), triethylamine (50 cm ³ ), and pyridine (50 cm ³ ) is refluxed 3 h, then the solvents are distilled off and the distillation residue is washed 3 times with water (100 cm ^{3 each} ) .The solid product is separated and dried, and recrystallized from dimethylsulphoxide.

If proceeded as described above Isolate from the corresponding starting materials:

a. 2- (2-benzothiazolyl) -1,3-indanedione, m.p. 352-354 ° C, of the general formula C 18 H 8 NO 2 S (M = 279.3), calculated:

% C, 68.80;% H, 3.25;% N, 5.01;% S, 11.58;

C, 68.91; H, 3.22; N, 5.08; S, 11.56. UV (DMSO? - 379 nm).

b. 4-NO ₂ -2- (2-benzothiazolyl) -1,3-indanedione, mp 293-295 ° C and the general formula C ₁₆ H ₈ N ₂ O ₄ S (M = 324.3), calculated:

H, 2.49; N, 8.64; S, 9.89. Found:

58.95% C, 2.41% H, 8.66% N, 9.80% S. UV (DMSO) 475 nm.

c. 5-NO _and 2- (2-benzothiazolyl Jl, 3-indandiones; mp 360-367 DEG C. (dec.) And the empirical formula _{C) R,} H, _{N 2} O ₄ S (M = 324.3) calc :

H, 2.49; N, 8.64; S, 9.89. Found:

% C, 59.33;% H, 2.14;% N, 8.38. S. UV (DMSO) 390 nm.

Claims (4)

1. X-2- (2-Benzothiazolyl) -1,3-indanediones of formula I INVENTION where X is H, _4-NO2, 5-NO _2nd 2. Preparation of compounds of formula I according to claim 1, characterized in that the phthalic anhydride is condensed or _3-NO2 or _4-NO2 derivative 2methylbenzothiazole in pyridine and triethylamine at reflux.