CS269448B1 - Sulphonamide derivatives - Google Patents

Abstract

The present invention relates to compounds of general formula X. The compounds are novel and are prepared by reacting p-acetylaminobenzenesulfonyl chloride with sulfonamides of general formula II, in which X represents a group as in formula I, by the action of an aqueous solution of sodium hydroxide and subsequent alkaline deacetylation of the acetyl protecting group. The compounds are used as chemotherapeutic agents.

Description

These new, previously undescribed substances are antibacterially active. Very good results were achieved with the substance with the ethyl isoxazole residue.

The substances according to the invention were prepared by the reaction of p-acetylaminobenzenesulfonyl chloride with sulfonamides of the general formula II

(II), in which X represents a group as in formula I, by treatment with an aqueous solution of sodium hydroxide followed by alkaline deacetylation of the acetyl protecting group.

The substances according to the invention are prepared by first condensing p-acetylaminobenzenesulfonyl chloride with the corresponding sulfonamide, namely by dissolving the sulfonamide in water with the addition of sodium hydroxide and simultaneously adding p-acetylaminobenzenesulfonyl chloride to the solution while maintaining the pH at 8 to 9 by further addition of sodium hydroxide solution at a temperature of 50 to 60 °C. The condensation time depends on the type of sulfonamide and ranges from 8 to 10 hours. The course of the reaction is monitored chromatographically. After the reaction is complete, the solution is filtered with the addition of activated carbon and the product is separated by acidification with acetic acid or dilute hydrochloric acid to pH 4.5 to 5.5 depending on the type of sulfonamide. The product is filtered off with suction, washed with water and, after the addition of an excess of 3N aqueous sodium hydroxide solution, deacetylated at a temperature of 50 to 80 °C. The reaction time varies (2 to 15 hours). The end of the reaction is monitored by a solubility test in 1N hydrochloric acid. After the deacetylation is complete, the product is separated by acidification with acetic acid or dilute

CS 269 448 B1 with hydrochloric acid to pH 5.5. The final products are purified by crystallization from dilute ethanol or precipitation with acetic or hydrochloric acid from aqueous alkaline solutions.

The antibacterial activity was determined by determining the initial inhibitory concentration. The antibacterial activity of known sulfonamides, such as sulfanilamide, 5-methyl-3-(p-aminobenzenesulfonylamino)isoxazole/sulfamethoxazole), 3-ethoxy-6-(p-aminobenzenesulfonylamino)pyridazine (sphofadazine) and 4-aminomethylbenzenesulfonamide (marfanil), was compared.

A total of 54 bacterial strains were used for the tests, see table:

Number of tribes

Streptococcus pyogenes Str. A5

-*- ' faecalis D8

Staphylococcus sureus9 epidermidis 8.

Escherichia coli10

Proteus sp.7

Citrobacter sp.2

Enterobacter sp.3

Klebsiela sp.2

Cultivation soils:

Brain - Heart Infusion (Oxoid) Mueller - Hinton broth (Imuna) + 5% lysed horse blood

Solvent:

0.1H NaOH ·

Determination of the minimum inhibitory concentration: It was carried out by the dilution method in liquid medium on plates using microtiter instruments from Dynatech. The minimum inhibitory concentration of substances was determined as the lowest concentration of the substance that inhibits the growth of the tested strain. The tested concentrations of the tested substances were in the range of 512 to 4 mg/1. The preparation of the inoculum of bacterial strains was carried out by the standard method. The results were read after 24 hours of cultivation at 37 °C.

Of the tested substances, the substance with a methylisoxazole residue had good antibacterial activity (8 to 16 mg/1) against strains of the Enterobacteriaceae family, and against gram-positive microorganisms, it had significant antibacterial activity (8 to 16 mg/1 against strains of Staphylococcus aureus.

Acute toxicity assessment:

Furthermore, acute toxicity was determined after a single oral administration of substances with a metal probe into the stomach in male mice of the NMRI Konárovice strain weighing 25 to 30 g.

The experimental groups consisted of 10 animals each.

5-ethyl-3-(p-aminobenzenesulfonylamino)isoxazole /Sulphamethoxazole/ - standard substance g/kg0/10 g/kg2/10 g/kg5/10

5-methyl-3-(4-[p-aminobenzenesulfonylamino]benzenesulfonylamino)isoxazole /new substance/ 1 g/kg0/10 g/kg0/1 0 g/kg0/10

25$ diethyl sulfoxide (1 ·1/20 g) 0/10

CS 269 448 Bl _?

At a dosage of 1 g to 10 g per 1 kg of body weight, no mouse deaths were recorded with the new substance, while with the standard substance, 2 mice died at 5 g and 5 mice at 10 g.

The results show that the new substance is comparable in antibacterial efficacy to one of the most effective sulfonamides to date (sulfanethoxazole), but has significantly lower toxicity.

The following examples of embodiments of the substance according to the invention are merely illustrative, but in no way limiting.

Example 1

5-methyl-3-(p-aminobenzenesulfonylamino)isoxazole (sulfamethoxazole) (12.66 g; 0.05 mol) and water (100 ml) are added to 50 ml of the above sodium hydroxide solution (8 g; 200 ml of water; 0.2 mol). The mixture is heated to 50 °C with stirring and, after the sulfamethoxazole has dissolved, p-acetylaminobenzenesulfonyl chloride (21.15 g; 0.06 mol; 66.3% strength) is added over a period of 2 hours. The mixture is stirred at 50 °C for a further 5 hours, maintaining the pH at 9 and 10 with the remaining sodium hydroxide solution (150 ml). The solution is filtered with activated carbon and the product is separated by adding dilute hydrochloric acid (1:1) to pH 5.5 (16.5 ml). The mixture is filtered with suction and washed with water (150 ml). After drying at 60°C, 18 g (79.9%) of 5-methyl-3-[4-(p-acetylaminobenzenesulfonylamino)benzenesulfonylamino]oxazole with a melting point of 136-141°C was obtained.

Deacetylation:

5-methyl-3-/4-(p-acetylaminobenzenesulfonylalanine)benzenesulfonylalanine/isoxazole (15 g; 0.033 mol) is added to the above sodium hydroxide solution (150 ml; 3 N) and heated with stirring at 80 °C for 15 hours. The solution is filtered with activated carbon and at 60 °C the product is precipitated by adding dilute hydrochloric acid (1:1; 65 ml) to pH 5.5. It is filtered off with suction and washed with water (150 ml).

After drying at 60 °C, 12 g (89.08%) of 5-methyl-3-/4-(p-aminobenzenesulfonylamino)benzenesulfonylamino/isoxazole were obtained, which after recrystallization from 50% ethanol (200 ml) had a melting point of 230-233 °C, was chromatographically pure and the elemental analysis corresponded to the given formula.

Example 2

By a procedure analogous to that of Example 1, 19 g (79.59%) of 3-methoxy-6-[4-(p-acetylaminobenzenesulfonylamino)benzenesulfonylamino]pyridazine with a melting point of 186 to 189 °C were obtained from 14 g (0.05 mol) of 3-methoxy-6-sulfanilanidopyridazine (Spofadazine) and p-acetylseinobenzenesulfonyl chloride (26.03 g; 0.078 mol; 70.156 ml).

Deacetylation with excess 3N sodium hydroxide (325 nl) gave 29.6 g (99%) of the final substance from 32.5 g (0.068 mol) of the previous acetyl derivative. The product was purified after dissolution in dilute sodium hydroxide (35 ml; 3 N; 250 ml of water) by precipitation with dilute hydrochloric acid (1:1) at 80 °C to pH 5.5. It was filtered off with suction, washed with water (100) and dried at 60 °C. The purified substance had a melting point of 235 to 238 °C. It was chromatographically pure and the elemental analysis was satisfactory.

Example 3

As in Example 1, 13.92 g (0.05 mol) of 4,6-dimethyl-2-sulfanilamidopyrimidine (Sulfadinidine) and 17.54 g (0.05 mol; 66.6%) of p-acetylaminobenzenesulfonyl chloride gave 7 g (71.52%) of 4,6-dimethyl-2-[4-(p-acetylaminobenzenesulfonylamino)benzenesulfonylamino]pyrimidine with a melting point of 239-241 °C.

Deacetylation of 15 g (0.03 mol) of the previous acetyl derivative with 3N sodium hydroxide (150 ml) was followed by acidification with hydrochloric acid (1:5; 250 ml) to pH 5.5, filtration with suction, washing with water (100 ml) and drying at 60 °C to give 12 g (92.3%) of 4,6-dimethyl-2-(4-(p-aminobenzenesulfonyltonino)benzenesulfonylamino/pyrimidine. After crystallization from 70% ethanol (260 ml), the product had a melting point of 252 to 253 °C. It was chromatographically pure and the elemental analysis was satisfactory.

Claims (1)

SUBJECT OF THE INVENTION Sulfonamide derivatives of the general formula I in which X represents