DE1115739B - Process for the preparation of 1-phenyl-5- (benzenesulfonamido) -pyrazoles - Google Patents

Description

GERMAN

PATENT OFFICE

C 19213 IVd / 12p

REGISTRATION DATE: JUNE 15, 1959

NOTICE THE REGISTRATION AND ISSUE OF EDITORIAL: OCTOBER 26, 1961

The invention relates to the preparation of l-phenyl-5- (benzenesulfonamido) pyrazoles in general formula

L NH-SO —— / '

N "

where R is hydrogen or a methyl radical, and their salts.

The new compounds can be used by methods known per se for the preparation of substituted Gain sulfonamides. The method consists e.g. B. in that one compounds of the formula

_SO ₂ -

wherein R has the meaning given at the beginning with l-phenyl-5-Y-pyrazoles or their dihydro derivatives implemented in a manner known per se, with X and Y contained in one of them with the exception of one Imino group, - NH -, splitting off during the reaction Radicals denote any dihydropyrazole compounds obtained by customary methods oxidized to pyrazole compounds and optionally converted the compounds obtained into salts.

So you can, for example, an unsubstituted in the p-position or, as indicated above, substituted benzenesulfonic acid halide, e.g. B. benzene or toluenesulfonic acid chloride, react with l-phenyl-5-aminopyrazole, usually as a by-product a diacyl product is also obtained. The implementation according to the process is advantageous in the presence carried out by diluents and / or condensing agents, for example anhydrous pyridine. The implementation takes place even under mild conditions, e.g. B. at room temperature instead. Advantageously begins one at room temperature and the reaction mixture is heated after the exotherm has subsided Reaction on the steam room.

The oxidation, which may be necessary, can be carried out in a conventional manner, for. B. using oxidizing agents, such as iron (III) salts, hydrogen peroxide, can be made.

Salts can be obtained from the new compounds in the usual way, e.g. B. by implementing with Method of manufacture

of l-phenyl-5- (benzenesulfonamido) -

pyrazoles

Applicant: CIBA Aktiengesellschaft, Basel (Switzerland)

Representative: Dipl.-Ing. E. Splanemann, patent attorney, Hamburg 36, Neuer Wall 10

, Claimed priority:

Switzerland of June 25 (No. 61 001) and December 5, 1958 (No. 66 961)

Dr. Jean Druey, Riehen,

Dr. Paul Schmidt, Therwil,

Dr. Max Wilhelm and Dr. Kurt Eichenberger, Basel

(Switzerland),
have been named as inventors

Bases such as alkali, alkaline earth, ammonium hydroxide or organic bases.

The new compounds have valuable pharmacological properties. They promote liver function for liver damage and can accordingly be used as a remedy. 5-benzenesulfonamido-1-phenyl-pyrazole is particularly valuable the formula

NH-

and its salts, particularly alkali metal salts.

The invention is described in more detail in the following examples. The temperatures are in degrees Celsius specified.

example 1

In a solution of 15.9 g of 5-amino-l-phenyl-pyrazole in 70 cm ^{3 of} anhydrous pyridine are within

109 710/480

added about 30 minutes 19.1 g of p-toluenesulfonyl chloride. The temperature rose to 55 ⁰ C. After the reaction is heated for 1 hour at 90 to 95 ° internal temperature. The reaction solution is then poured into 400 cm ^{3 of} 1 η-hydrochloric acid and, after standing overnight, the precipitate is filtered off with suction. The latter is ^{thoroughly stirred in 250 cm 3 of} 0.5 N sodium hydroxide solution. A little undissolved Np-toluenesulfonyl-5- (p-toluenesulfonamido) -l-phenyl-pyrazole with a melting point of 207 ° to 208 ° is then filtered off with suction, the filtrate is adjusted to pH = 2 to 3 with 2η hydrochloric acid and filtered again from the failed product. This is recrystallized from benzene. 5- (p-Toluenesulfonamido) -l-phenyl-pyrazole of the formula

15 again from the failed product. This will recrystallized from isopropyl ether. 5- (o-Toluenesulfonamido) -l-phenyl-pyrazole of the formula

-NH-SO ₂

CH _S

—NH- SO ₉

; -CH ₃

is obtained in colorless crystals from 111 to 113 °.

Claims (4)

PATENT CLAIMS: 1. Process for the preparation of 1-phenyl-5- (benzenesulfonamido) -pyrazoles the general formula is obtained in colorless crystals with a temperature of 142 to 144 °. Example 2 17.7 g of benzenesulfonyl chloride are introduced into a solution of 15.9 g of 1-phenyl-5-aminopyrazole in 80 cm ^{3 of} anhydrous pyridine within about 10 minutes. After the reaction has subsided, the mixture is heated to an internal temperature of 90 to 95 ° for a further hour. The reaction solution is then poured into 400 cm ^{3 of} 1 η-hydrochloric acid and, after standing overnight, the precipitate is filtered off with suction. The latter is dissolved in 300 cm ^{3 of} 1N sodium hydroxide solution, then a little undissolved material is sucked off. The filtrate is then adjusted to pn 3 to 4 with 2N hydrochloric acid and the precipitated product is filtered off again. This is recrystallized from a little alcohol. 5- (Benzolsulfonamido) -l-phenyl-pyrazole of the formula l:
N -NH-SO, 45 50 is obtained in colorless crystals from 132 to 133 °. Example 3 19.1 g of o-toluenesulfonyl chloride are introduced into a solution of 15.9 g of 5-amino-1-phenyl-pyrazole in 80 cm ^{3 of} anhydrous pyridine over the course of 10 minutes. The temperature rises up to 50 °. After the reaction has subsided, the mixture is heated to an internal temperature of 90 to 95 ° for a further hour. The reaction solution is then poured into 400 cm ^{3 of} 1 η-hydrochloric acid and, after standing overnight, the precipitate is filtered off with suction. It is now dissolved in 300 cm ^{3 of} 1 N sodium hydroxide solution, a little undissolved material is filtered off with suction, the filtrate is then adjusted to pn 3 to 4 with 2 η hydrochloric acid and filtered -NH-SO ₂ or their salts, in which R is hydrogen or a methyl radical, characterized in that compounds of the formula SO ₂ -X in which R has the meaning given above, with l-phenyl-5-Y-pyrazoles or their dihydro derivatives implemented in a manner known per se, with X and Y in one of them with the exception of one contained imino group, - NH -, radicals split off in the reaction mean, optionally obtained dihydropyrazole compounds oxidized by customary methods 2x1 pyrazole compounds and optionally converting the compounds obtained into salts. 2. The method according to claim 1, characterized in that one benzenesulfonic acid halides the formula "V- SO ₉ -HaI where R has the meaning given above and Hal is a halogen atom, in particular chlorine, with l-phenyl-5-aminopyrazole or its dihydro derivative. 3. Process according to Claims 1 and 2, characterized in that the reaction is carried out in Executes the presence of a diluent and / or condensing agent. 4. Process according to Claims 1 to 3, characterized in that the reaction is carried out in The presence of anhydrous pyridine. Considered publications:
HeIv. chim. Acta, 41 (1958), pp. 306-309. When the application was announced, two priority documents and two pages of test report were laid out. © 109 710/480 10.61