CS265433B1 - 2-nitrochlorobenzene-4- (N, 4'-carboxyphenyl) sulfonamide; - Google Patents

Abstract

The solution falls into the field of chemistry of organic dyes and pigments and preparations for moth protection. The aim of the solution is the compound 2-nitrochlorobenzene-4-(N,4’-carboxyphenyl)sulfonamide and a method for its preparation. The method for preparing 2-nitrochlorobenzene-4-(N,4 1-carboxyphenyl)- sulfonamide of the formula I Cl LO. no2 (I) so2-nh consists in reacting a water-soluble salt of 4-aminobenzoic acid in an aqueous medium and 2-nitrochlorobenzene-2-sulfonyl chloride at pH 2 to 9, preferably pH 5 to 7. The preferred pH range is maintained within a specified range during synthesis by a regulating pH meter with blocking the sodium hydroxide inflow or by working in a suitable buffer environment - e.g. bicarbonate.

Description

(57) The solution falls within the field of chemistry of organic dyes and pigments and antimoll protection products. The object of the present invention is the compound 2-nitrochlorobenzene-4- (N, 4'-carboxyphenyl) sulfonamide and a process for its preparation. Preparation of 2-nitrochlorobenzene-4- (N, ¹ 4 -karboxyfenyl) sulfonamide of formula I

Cl

LO.

no ₂ (I) with _2- nm

consists in reacting the water-soluble salt of 4-aminobenzoic acid in an aqueous medium and with 2-nitrochlorobenzene-2-sulfonyl chloride at a pH of 2 to 9, preferably a pH of 5 to 7. The preferred pH range is maintained within a certain range -meter to block the influx of sodium hydroxide or working in a suitable buffer - such as bicarbonate.

CS 265 433 Bl

The invention relates to 2-nitrochlorobenzene-4- (N, 4 -karboxyfenyl ¹⁾ sulphonamide and its production method.

Compound was prepared 2-nitrochlorobenzene-4- (N, 4 -karboxyfenyl ¹⁾ sulfonamide which may be used for further syntheses in chemistry of organic dyes and pigments or in the preparation of moth means.

A process for the preparation of 2-nitrochlorobenzene-4- (N, 4'-carboxyphenyl) sulfonamide of formula X

Cl

characterized in that the water-soluble salt of 4-aminobenzoic acid is reacted with 2-nitrochlorobenzene-4-sulfonyl chloride in an aqueous medium at a pH of 2 to 9, preferably a pH of 5 to 7.

In the actual synthesis, the preferred pH range is maintained within a specified range by means of an automatic pH-regulating meter with blocking of sodium hydroxide influx or working in a suitable buffer - e.g., bicarbonate.

Embodiments of the invention are illustrated by the examples.

Example 1

13.9 g of 100% 4-aminobenzoic acid are suspended in 100 ml of water and dissolved to pH 7.5 by addition of sodium hydroxide solution. 25.6 g of 100% 2-nitrochlorobenzene-4-sulfonyl chloride (0.1 mol) was metered into the resulting solution evenly with efficient stirring at 20 to 50 ° C, and the resulting acid was blunted with sodium hydroxide solution c (NaOH) ) = 10 mol / l to form a solution with a pH of 5 to 7 continuously.

After several hours of reaction, the reaction mixture is heated to 50-60 ° C and acidified with stirring to a pH of 1 with c (HCl) = 9 mol / l hydrochloric acid.

The suspension of the compound of formula I is filtered off and the filter cake is washed with warm water until the acidic reaction of the filtrates is lost. 29.2 g of 100% of the compound of formula I of m.p. Mp 282-285 ° C.

Example 2

13.9 g of 100% 4-aminobenzoic acid are suspended in 100 ml of water and dissolved by the addition of 12.5 g of sodium bicarbonate. 25.6 g of 100% 2-nitrochlorobenzene-4-sulfonyl chloride (0.1 mol) are metered in evenly quickly with efficient stirring and at a temperature of 20 to 50 ° C and pH 8. The pH level is maintained at 5 to 7 during dosing and reaction. The actual rate of sulfonyl chloride dosing must also be controlled with respect to the foaming intensity of the reaction mixture.

After several hours of reaction, the reaction mixture was heated to 50-60 ° C and acidified to pH 1 with hydrochloric acid with stirring.

The solid of Formula I is filtered off and the filter cake is washed with warm water until the acidic reaction of the filtrates is lost, yielding 29.2 g of 100% of Formula I with the above m.p.

Claims (2)

SUBJECT OF THE INVENTION 1. 2-Nitrochlorobenzene-4- (N, 4'-carboxyphenyl) sulfonamide of formula I (I) 2. A process for preparing 2-nitrochlorobenzene-4- (N, 4 -karboxyfenyl ¹⁾ of the sulfonamide of the formula I according to claim 1, wherein the water soluble salt of 4-aminobenzoic acid are reacted in a water environment therein with 2-nitrochlorobenzene-4-sulfonyl chloride at pH 2 to 9, preferably 5 to 7.