CS233445B1 - Substituted 4-anilino-1,3-dimethyl-1 H -pyrazolo [3,4-b] oxiryls and processes for their preparation - Google Patents

Abstract

The invention relates to substituted 4-anilino-1,3-dimethyl-1H-pyrazolo[3,4-b] oquinolines of the general formula I HN Ί CH, (I) CH3 in which R1 denotes a hydroxy group, a methoxy group, a propyloxy group, a cetyloxy group, an ethoxycarbonylmethoxy group, a dimethylamino group, a carboxy group or a phenyl group and R2 denotes a hydrogen atom, or R1 is a hydrogen atom and R2 is a methoxy group, or R1 and R2 are methoxy groups, or R1 is an acetamido group and R2 is a methyl group, or R1 and R2 together form a methylenedioxy group. These new, previously undescribed substances show antiviral activity against the A2-Hong Kong influenza virus, against the encephalomyocarditis virus and against the vaccinia virus in mice.

Description

The invention relates to substituted 4-enylino-1,3-dimethyl-1H-pyrazolo[3,4-b]quinolines of the general formula I

wherein R ¹ represents a hydroxy group, a methoxy group, a propyloxy group, a cetyloxy group, an ethoxycarbonylmethoxy group, a dimethylamino group, a carboxy group or a phenyl group and

R ² represents a hydrogen atom, or R is a hydrogen atom and R ² is a methoxy group, or R and R ² are

2 1 2 * methoxy group, or R is an acetamido group and R is a methyl group, or R and R together form a methylenedioxy group. The invention also relates to a process for the preparation of substituted 4-anilino-1,3-dimethyl-1H-pyrazolo[3,4-b] chlorolines of general formula 1.

These new, previously undescribed compounds exhibit antiviral activity against influenza A2-Hong Kong virus, encephalomyocarditis virus, and vaccinia virus in mice. *

Compounds of the general formula I can be prepared according to the invention by the reaction of the known 4-chloro-1,3-dimethyl-1H-pyrazolo[3,4-b]-quinoline (Stein R. O., Biel J. H., J. Med.

Chem. 13, 153 O973j] with the appropriate aniline derivative in phenol at a temperature of 80 °C to 120 °C, preferably at a temperature of 100 °C. Compounds of general formula 1, where R' is a propyloxy group or an ethyloxy group and R ² is a hydrogen atom, can be prepared according to the invention by alkylation of the compound.

of the general formula 1, where R is a hydroxy group and R is a hydrogen atom, with the corresponding alkyl bromide in acetone in the presence of anhydrous potassium carbonate and preferably in the presence of potassium iodide.

The compounds of the invention belong to the group of substances with antiviral effects. The compounds were evaluated in the form of hydrochlorides against A2-Hong Kong virus and against encephalomyocarditis virus (EMC) in mice. For some compounds, activity against vaccinia virus in mice was also demonstrated.

Evaluation of efficacy against influenza A2-Hong Kong virus in mice:

Female SPF (Velaz) white mice weighing 10 to 11 g were used. The virus was administered intranasally to the mice under light ether anesthesia. The LD^q amount of the virus was determined in a separate experiment and was calculated according to REED and MUENCH / Řeed L. J., Muench H.: Amer. J. Hyg. 27, 493 (1938)/. 7 mice were used for each concentration of virus. Untreated mice died of pneumonia depending on the concentration of virus used 3 to 10 days after infection. The tested substances were suspended using monoester of oleic acid with tripolyethylene glycol hydrosorbite ether (Tween 80). The substances were administered to the animals per os by gavage, or were administered subcutaneously into the fold of skin on the back, always in a volume of 0.2 ml. Mice were treated orally or subcutaneously twice daily for 5 days (1 day before and 4 days after infection). The dose was 150 mg/kg. Efficacy was assessed by prolongation of the mean survival time compared to untreated controls.

After oral administration, compounds of general formula 1, where R ¹ is a methoxy group and R ² is a hydrogen atom, were effective (extending the survival time of mice against the 5 virus by 50-56), where

R ¹ is a hydroxy group and R ² is a hydrogen atom (extends the survival time of mice against 5 ^LD 5q virus by 66% and against 50 LC^q virus by 15%) and where R ¹ and R ² together form a methylenedioxy group (extends the survival time of mice against 50.LDgQ virus by 25%).

Compounds of general formula I which have activity against influenza A2-Hong Kong virus in mice after subcutaneous administration are summarized in Table 1 and are presented in terms of the increase in mean survival time in %.

Table I

R ¹ R ² 0.5 ld ₅₀ (%) 5 _LD50 (%) 50 _LD50 (%) OCH ₃ H 59 - 46 THEM ₃ ) ₂ H - - 105 COOH H - 35 49 OH H - 46.5 70 OC3H7 H - 61 - ^OC 16 ^H 33 H - 63 - -o-ch ₂ -o- - 44 - 0CH ₂ C00C ₂ H ₅ H - 75 H oh ₃ 60 60 0 OCH ₃ oh ₃ 49 44 0 ^{C6H5 ​} The 21 37.5 0

Explanations to Table 1:

-......not tested

Evaluation against EMC virus in mice:

*

White SPF mice (Velaz) weighing 10 to 11 g were used. The virus was injected subcutaneously into the back skin fold in a volume of 0.2 ml. Untreated mice died 3 to 7 days after infection, depending on the concentration of the virus used. Subcutaneous treatment was performed with four doses of 100 mg/kg, 28, 22, 2 hours before and 2 hours after infection. Oral treatment was performed 24 hours before infection with a single dose of 400 mg/kg. Determination of the amount of virus used and evaluation of the efficacy of the substances were performed in the same way as in the evaluation of efficacy against the A2-Hong Kong influenza virus.

The efficacy of the compounds of general formula I against EMC virus in mice after oral (p.o.) and subcutaneous (a.p.) administration of these substances is shown in Table II in the prolongation of the average survival time of mice in % after application of a dose of 5 LD^q of virus.

Table II

R ¹ R ² p. O· (%) With C* W OH H 0 66 _3:00 p.m. ₇ H 32 33 ^OC 16 ^H 33 H 47 83 -o-ch ₂ -o- 47 95 0CH ₂ C00C ₂ H ₅ H 50 100 NHCOCH ₃ ch ₃ 0 40 ^C 6«5 H 0 36

233445 4

Evaluation against vaccinia virus in mice:

Vaccinia virus as a lyophilized vaccine Sevac (ÚSOL Prague). The vaccine contains 5x10? units of virus in 1 ml. Female white SPF mice (Velaz) weighing 15 g were used. The virus was administered intravenously to the mice, in a volume of 0.1 ml 1.25 x 10^ units of virus were administered, which caused the formation of approximately '00 necrotic forests on the tail of untreated mice 6 to 6 days after infection. To make it easier to count the forests, the tails were stained with a solution containing 1% fluorescein and 0.5% methylene blue, which stained necrotic tissue. The skin forests healed spontaneously after 14 days and the symptoms of the disease disappeared. The treatment was carried out in the same way as for the evaluation of the effectiveness against the EMC virus. The effectiveness was assessed according to the percentage reduction in the number of necrotic forests compared to the untreated control.

The efficacy against vaccinia virus in mice was determined for compounds of general formula I, where R ¹ is methoxy-eupine or a dimethylamino group and R ² is a hydrogen atom. Compound 1 2 of general formula I, where R is a dimethylamino group and R is a hydrogen atom, reduces the number of lesions after oral administration by .82% and after subcutaneous administration by 74%. ' ♦

As can be seen from the data, the compounds of general formula I are active against the A2-Hong Kong virus, against the EMC virus and against the mouse vaccinia virus. The preparation method is simple and provides the desired products in satisfactory yields. More details are given in the following examples. The examples given are intended to illustrate the invention and not to limit it.

Example

4-(4-Methoxyanilino)-1,3-dimethyl-1H-pyrazolo/3,4-b/quinoline

A mixture of 2.32 g of 4-chloro-1,3-dimethyl-1H-pyrazolo[3,4-b]quinoline (10 mmol), 1.35 g of 4-methoxyaniline (11 mmol) and 15 g of phenol was stirred for 1 hour at 100 °C.

The reaction mixture was poured into 100 ml of 2M sodium hydroxide solution, the insoluble fraction was filtered off, washed with water and then dissolved in 200 ml of 10% acetic acid under boiling. The filtrate after filtering off the insoluble fraction was cooled and made alkaline with 3M sodium hydroxide solution. The precipitated substance was filtered off, washed with water and recrystallized from 3.0% aqueous dimethylformamide. 2.2 g of substance (69.2%) with a melting point of 154.4 to 155.4 °C was obtained. After dissolving in ethanol, the substance was converted into hydrochloride with a melting point of

201.1 to 202.4°C.

»

Example 2

4-(4-H.methylaminoanilino)-1,3-dimethyl-1H-pyrazolo/3,4-b/ quinoline

Stašs 1.16 g of 4-chloro-1,3-dimethyl-1H-pyrazolo/3,4-b/quinoline (5 mmol), 0.75 g of 4-dimethylaminoaniline (5.5 mmol) and 7 g of phenol were stirred for 1 hour at 100 °C. After dilution with 25 ml of ethanol, the solution was precipitated with ether, the precipitate was washed with ether and dissolved in water acidified with a few drops of hydrochloric acid. The insoluble part was filtered off and the filtrate was basified with 2M sodium hydroxide solution to pH 10. The precipitated substance was filtered off with suction and washed with water. After dissolution in ethanol, the blue solution was poured through a column of 100 g of silica gel (Kieselgel 60 Merck). The blue solution passed through the column was evaporated to dryness, 1.33 g of substance (80.3%) was obtained, 0 m.p. 79.6 °C to 81.3 °C. The residue was dissolved in hot water in 10 ml of ethanol and the solution was acidified with a few drops of ethanolic hydrogen chloride. The crystals that separated after cooling were filtered off with suction and recrystallized from ethanol. 1.52 g of the substance (75.2%) with a melting point of 237.9 °G to 239.7 °C were obtained.

Example 3

4-(4-Hydroxyanilino)-1,3-dimethyl-1H-pyrazolo-/3,4-b/quinoline hydrochloride

A mixture of 2.32 g of 4-chloro-1,3-dimethyl-1H-pyrazolo[3,4-b]chloroline (10 mmol), 1.21 g of 4-aminophenol (11 mmol) and 15 g of phenol was stirred for 1 hour at 100 °C. After dilution with 50 ml of ethanol, the mixture was precipitated with ether. The insoluble fraction was filtered off with suction, washed with ether and recrystallized from ethanol. 3.1 g of the substance (91.0%) was obtained. mp 346 ° ^C to 352 °C (with decomposition).

Example 4

4-(4-Ethoxycarbonylmethoxyanilino)-1,3-dimethyl-1H-pyrazolo[3,4-(b)quinoline hydrochloride

A mixture of 2.78 g of 4-chloro-1,3-dimethyl-1H-pyrazolo[3,4-b]quinoline (12 mmol), 2.55 g of 4-ethoxycarbonylmethoxyaniline (13 mmol) and 20 g of phenol was stirred for 2 hours at 100 °C. By the same working-up method as in Example 3, 2.95 g of the substance (57.6 %) with a melting point of 199.2 °C to 203.8 °C was obtained.

Example 5

4-(4-Carboxyanilino)-1,3-dimethyl-1H-pyrazolo-[3,4-b]quinoline hydrochloride.

A mixture of 2.32 g of 4-chloro-1,3-dimethyl-1H-pyrazolo/3,4-b/quinoline (10 mmol), 1.65 g of 4-aminobenzoic acid (12 mmol) and 15 g of phenol was stirred for 8 hours at 100 °C. After dilution with 50 ml of ethanol, the mixture was precipitated with ether. The insoluble fraction was filtered off with suction, washed with ether and boiled in acetone. 2.7 g of the substance (73.2%) with a melting point of 308 °C to 310 °C was obtained.

Example6

4-(4-Biphenylamino)-1,3-dimethyl-1H-pyrazolo/3,4-b/-quinoline hydrochloride

A mixture of 1.85 g of 4-chloro-1,3-dimethyl-1H-pyrazolo[3,4-b]quinoline (8 mmol), 1.49 g of 4-aminobiphenyl (8.8 mmol) and 10 g of phenol was stirred at 100 °C for 4 hours.

By the processing method described in Example 3, 1.8 g of the substance (56.1%) with a melting point of

207.3°C to 211.8°C.

Example 7

4-(3-Methoxyanilino)-1,3-dimethyl-1H-pyrazolo-/3,4-b/quinoline hydrochloride

A mixture of 0.46 g of 4-chloro-1,3-dimethyl-1H-pyrazolo[3,4-b]quinoline (2 mmol), 0.26 g of 3-methoxyaniline (2.1 mmol) and 3 g of phenol was stirred at 100°C for 2 hours.

By the same processing method as in Example 3, 0.44 g of a substance with a melting point of 151.0-154.7°C was obtained.

Example 8

4-(3,4-dimethoxyanilino)-1,3-dimethyl-1H-pyrazolo/3,4-b/quinoline hydrochloride

A mixture of 1.74 g of 4-chloro-1,3-dimethyl-1H-pyrazolo/3,4-b/quinoline (7.5 mmol), 1.26 g of 3,4-dimethoxyaniline (8.25 mmol) and 10 g of phenol was stirred for 2 hours at 100 °C. By the same working-up method as in Example 3, 1.82 g of the substance (63.0%) with a melting point of 208.6 °C to 218.7 °C (with decomposition) was obtained.

Example 9

1,3-Dimethyl-4-(3,4-methylenedioicaniline)-1H-pyrazolo[3,4-b]quinoline hydrochloride

A mixture of 2.32 g of 4-chloro-1,3-dimethyl-1H-pyrazolo[3,4-b]quinoline (10 mmol), 1.51 g of 3,4-methylenedioxyaniline (11 mmol) and 15 g of phenol was stirred for 1 hour at 100 °C. By the same treatment as in Example 3, 3.1 g of the substance (84.0%) with a melting point of 251.0 °C to 252.8 °C were obtained.

Example

4-(4-acetamido-3-methylanilino)-1,3-dimethyl-1H-pyrazolo/3,4-b/quinoline hydrochloride

A mixture of 2.32 g of 4-chloro-1,3-dimethyl-1H-pyrazolo/3,4-b/quinoline (10 mmol), 1.8 g of 5-amino-2-acetamido toluene (11 mmol) and 15 g of phenol was stirred for 1 hour at 100 °C. In the same manner as in Example 3, 2.32 g of the substance (58.6%) with a melting point of 238.6 °C to 241.8 °C was obtained.

They applied

1,3-Dimethyl-4-(4-propoxyanilino)-1H-pyrazolo-[3,4-b]quinoline hydrochloride

To a suspension of 1.7 g of 4-(4-hydroxyanilino)-1,3-dimethyl-1H-pyrazolo[3,4-b] quinoline hydrochloride (5 mmol) in 150 ml of dry acetone were added 2.05 g of anhydrous potassium carbonate and 0.15 g of potassium iodide and 10.7 g of propyl bromide (5.5 mmol). The mixture was refluxed for 80 hours with stirring. After evaporation to dryness, the residue was extracted with chloroform after dilution with 25 ml of water. The extract was shaken with 5% sodium hydroxide solution and dried with magnesium sulfate. The filtrate after evaporation to dryness was dissolved in 2-propanol and acidified with hydrochloric acid. The crystals separated after cooling were filtered off with suction and recrystallized from ethanol. 0.97 g of the substance (50.7%) was obtained. m.p. 199°C to 202.6°C.

Example 12

4-(4-Cetyloxyanilino)-1,3-dimethyl-1H-pyrazolo/3,4-b/chicholine hydrochloride

From 1.7 g of 4-(4-hydroxyanilino)-1,3-dimethyl-1H-pyrazolo[3,4-b]quinoline hydrochloride (5 mmol) and 1.7 g of cetyl bromide (5.5 mmol) 1.15 g of substance (40.6%) with a melting point of 170.1 °C to 176.5 °C were obtained by the method described in Example 11. The substance was obtained by precipitation with ether from a solution in ethyl acetate.

Claims (3)

object of the invention Substituted 4-anilino-1,3-dimethyl-1H-pyrazolo [3,4-b] quinolines of general formula (I); (I) wherein R ¹ is methoxy, hydroxy, propyloxy, cetyloxy, ethoxycarbonylmethoxyacin, dimethylamino, carboxy or phenyl and R ² is hydrogen, Or wherein R is hydrogen and R is methoxy, or wherein both R and R are methoxy, or wherein R is acetamido and R is methyl, or wherein R and R together form ethylenedioxy. 2. Process for preparing compounds according to claim 1 of formula I wherein R is methoxy, hydroxy, ethoxykarbonylmethoxyskupina, dimethylamino, carboxy or phenyl slňipina and ^R2 is hydrogen, or wherein R ¹ is hydrogen and R ² is methoxy, or R ¹ R ² is methoxy, or wherein R ¹ is acetamido and R ² is methyl, or wherein R and R of the appellation are methylenedioxy, wherein 4-chloro-1,3-dimethyl-1H-pyrazolo [3,4] b) The quinoline is heated with an additional aniline derivative, preferably with a 0.1 molar excess, in phenol to a temperature of 80 ° C to 120 ° C, preferably to a temperature of 100 ° C. 3 Process for preparing compounds according to claim 1 of formula I wherein R ¹ is a propoxy or cetyloxyskupina and R ² is hydrogen, characterized in that a compound of vsorce I wherein R ¹ is hydroxy and R ² is hydrogen, alkylating the corresponding alkylbroid, wherein alkyl is propyl or cetyl, preferably in a 0.1 molar excess, in acetone in the presence of anhydrous potassium carbonate, preferably in the presence of potassium iodide.