CS252342B1 - Blue 1: 2 chromosome azo dye - Google Patents

Abstract

Blue 1:2 chromium complex dye for dyeing wool and PAD from a weakly acidic neutral bath is formed by a mixture of the dye of general formula I of constitution A, where M means Na, K, NH^ and X NO2 and Y H and constitution B, where M means Na, K, NH^ and X H and Y Cl in the ratio of constitution A:B * 0.05 to 99.5:99.5 to 0.5.

Description

The invention relates to O, N-substituted (3,4-b) quinolines of the formula I

4,9-Dihydro-6-hydroxy-2,3-dimethyl-4-oxo-2H-pyrazolo

R ¹ O

ΧΧΛΧ

CH, / 1 /,

Wherein R and R are hydrogen or methyl.

These novel substances, which have not been described yet, are useful as intermediates for the preparation of substances having significant biological effects, in particular antiviral and antitumor activity.

2

The compound of formula I wherein R is methyl and R is hydrogen may be prepared by cyclization of the well-known 3- (4-methoxyanilino) -1,5-dimethyl-1H-pyrazole-4-carboxylic acid by polyphosphoric acid at elevated temperature . A compound of formula (I) wherein both R ¹ and R ² is methyl may be prepared by methylation of the sodium salt according to the invention

4.9-Dihydro-6-methoxy-2,3-dimethyl-4-oxo-2H-pyrazolo [3,4-b] chimoline with methyl iodide, preferably at room temperature in dimethylformamide. The compound of formula X wherein R ¹ is hydrogen 9 and R is methyl may be prepared according to the invention from 4,9-dihydro-6-methoxy-2,3,9-trimethyl-4-oxo-2H-pyrazolo / 3, 4-b) quinoline by demethylation with azeotropic hydrobromic acid.

The process for preparing the substances is simple and provides the substances in satisfactory yields. The products obtained are directly usable for further processing. The examples given are merely illustrative and not limiting.

He did

4.9-Dihydro-6-methoxy-2,3-dimethyl-4-oxo-2H-pyrazolo [3,4-b] chloroline

A mixture of 3- (4-methoxvanylino) -1,5-dimethyl-1H-pyrazole-4-carboxylic acid (13.1 g, 50 mmol) and polyphosphoric acid (75 g, 85% ^Ρ 2 ° 5) was stirred at room temperature for 4 hours. 90 ° C. After addition (500 ml), the mixture was cooled, the insoluble material was aspirated and recrystallized from 50% aqueous dimethylformamide. 9.6 g (79%) of a melting point of 360 ° C were obtained.

Example 2

4,9-Dihydro-6-methoxy-2,3,9-trimethyl-4-oxo-2H-pyrazolo [3,4-b] quinoline

To a stirred suspension of 4,9-dihydro-6-methoxy-2,3-dimethyl-4-oxo-2H-pyrazolo [3,4-b] quinoline (12.2 g, 50 mmol) in dimethylformamide (200 mL) was added added 80%. sodium hydride (1.8 g, 60 mmol) and the mixture was stirred at room temperature for 1 hour. After addition of methyl iodide (8.5 g of 60 mmol), the mixture was stirred at room temperature for 8 hours. After addition of water (250 ml), the mixture was cooled, the insoluble material was aspirated and crystallized from ethanol. 12.1 g (94%) of m.p. Mp 191-193 ° C.

Example 3

4,9-Dihydro-6-hydroxy-2,3,9-trimethyl-4-oxo-2H-pyrazolo [3,4-b] quinoline

A mixture of 4,9-dihydro-6-methoxy-2,3,9-trimethyl-4-oxo-2H-pyrazolo [3,4-b] quinoline (5.1 g, mmol) and azetropic hydrobromic acid (70 ml) was refluxed for 5 hours. The insoluble matter precipitated upon cooling was aspirated and crystallized from ethanol. 3.9 g (79%) of a melting point of 360 ° C were obtained.

Claims (1)

SUBJECT OF THE INVENTION N, N-substituted 4,9-dihydro-6-hydroxy-2,3-dimethyl-4-oxo-2H-pyrazolo [3,4-b] quinolines of formula I Wherein R and R are hydrogen or methyl.