Isatine derivatives, their preparation and use

Abstract: A method of treatment with compounds having the formula wherein R¹ is hydrogen, C₁₋₆-alkyl which may be branched, C₃₋₇-cycloalkyl, benzyl, phenyl which may be substituted, acyl, hydroxy, C₁₋₆-alkoxy, CH₂CO₂R' wherein R' is hydrogen or C₁₋₆-alkyl which may be branched, CH₂CN, CH₂CONR IV R V wherein R IV and R V independently are hydrogen or C₁₋₆-alkyl, or CH₂C(=NOH)NH₂; R² is hydrogen, benzyl, C₁₋₆-alkyl which may be branched, or C₃₋₇-cycloalkyl; R⁴, R⁵, R⁶, R⁷ independently are hydrogen, C₁₋₆-alkyl which may be branched, phenyl, halogen, C₁₋₆-alkoxy, NO₂, CN, SO₂NR''R''' wherein R'' and R''' independently are hydrogen or C₁₋₆-alkyl, or CF₃; or R⁶ and R⁷ together form an additional 4 to 7 membered ring which may be aromatic or partial saturated and which may be substituted with halogen, NO₂, CF₃, CN, SO₂NR''R''' wherein R'' and R''' independently are hydrogen or C₁₋₆-alkyl, and R⁴ and R⁵ have the meanings set forth above, are disclosed, as well as pharmaceutical compositions thereof. Certain of the compounds are novel. The compounds and pharmaceutical compositions containing the compounds are useful in the treatment of central nervous system disorders and especially conditions sensitive to excitatory amino acids.

Description: The present invention relates to the use of compounds having excitatory amino acid antagonizing properties for preparing a medicament, pharmaceutical compositions comprising such compounds, and to novel compounds having excitatory amino acid antagonizing properties and to the preparation of such compounds. It is well known from Wiss, Z. Ernst-Moritz-Arndt-Univ. Greifswald, Math.-nat.wiss. Reihe 35 , 39-44 (1986) 4, Pharmazie 39 , H.10, 713 (1984), Pharmazie 37 , H.12, 858-861 (1982), Neuroscience Letters 107 , 327-330 (1989), PCT patent application International Publication Number WO 89/03818, and Khim.-Farm.zh. 23(11) , 1349-1352 (1989), that certain of the chemical entities comprised within the scope of method of treatment according to the present invention are known to possess biological activity. Chemical Abstracts vol. 103 (1985), abstract No. 16405s discloses indolinone derivatives which can function as reversible inhibitors of monoamine oxidase; some of the compounds showed low toxicity. An excitatory amino acid antagonizing property is not known from said compounds. EP-A-0010398 discloses isatin derivatives which are useful for treating allergic symptoms. And excitatory amino acid antagonizing property of said compound is not disclosed. It is an object of the present invention to provide novel compounds useful for the treatment of diseases in mammals, including a human, acting by antagonizing an excitatory amino acid in such mammal. Said object is achieved by compounds having the formula wherein R¹ is hydrogen, C₁₋₆-alkyl which may be branched, C₃-₇-cyclo alkyl, benzyl, acyl, hydroxy, C₁₋₆-alkoxy, CH₂CO₂R' wherein R' is hydrogen or C₁₋₆-alkyl which may be branched, CH₂CN, CH₂CONR IV R V where-in R IV and R V independently are hydrogen or C₁₋₆-alkyl, or CH₂C(=NOH)NH₂; R² is hydrogen, benzyl, C₁₋₆-alkyl which may be branched, or C₃₋₇-cycloalkyl; R⁵ is NO₂, F, CF₃, SO₂NR''R''' wherein R'' and R''' independently are hydrogen or C₁₋₆-alkyl, or CN; and R⁴, R⁶, R⁷ independently are hydrogen, C₁₋₆-alkyl which may be branched, phenyl, halogen, C₁₋₆-alkoxy, NO₂, CN, SO₂NR''R''' wherein R'' and R''' independently are hydrogen or C₁₋₆-alkyl, or CF₃, or R⁶ and R⁷ together form an additional 4 to 7 membered ring which may be aromatic or partial saturated and which may be substituted with halogen, NO₂, CF₃, CN, SO₂NR''R''' wherein R'' and R''' independently are hydrogen or C₁₋₆-alkyl, and R⁴ has the meaning set forth above, with the proviso that R⁵ is different from NO₂ and F when R¹, R⁴, R⁶ and R⁷ are hydrogen and R² is nydrogen or benzyl; and that R⁵ is different from NO₂ when R¹, R², R⁴ and R⁶ are hydrogen and R⁷ is NO₂. The further object of the present invention is to provide novel pharmaceutical compositions useful for the treatment of diseases in mammals, including a human, acting by antagonizing an excitatory amino acid in such mammal. Said object is achieved by a pharmaceutical composition comprising an effective excitatory amino acid antagonizing amount of a compound having the formula wherein R¹ is hydrogen, C₁₋₆-alkyl which may be branched, C₃₋₇-cyclo alkyl, benzyl, acyl, hydroxy, C₁₋₆-alkoxy, CH₂CO₂R' wherein R' is hydrogen or C₁₋₆-alkyl which may be branched, CH₂CN, CH₂CONR IV R V wherein R IV and R V independently are hydrogen or C₁₋₆-alkyl, or CH₂C(=NOH)NH₂; R² is hydrogen, benzyl, C₁₋₆-alkyl which may be branched, or C₃₋₇-cycloalkyl; R⁵ is NO₂, F, CF₃, SO₂NR''R''' wherein R'' and R''' independently are hydrogen or C₁₋₆-alkyl, or CN; and R⁴, R⁶, R⁷ independently are hydrogen, C₁₋₆-alkyl which may be branched, phenyl, halogen, C₁₋₆-alkoxy, NO₂, CN, SO₂NR''R''' wherein R'' and R''' independently are hydrogen or C₁₋₆-alkyl, or CF₃, or R⁶ and R⁷ together form an additional 4 to 7 membered ring which may be aromatic or partial saturated and which may be substituted with halogen, NO₂, CF₃, CN, SO₂NR''R''' wherein R'' and R''' independently are hydrogen or C₁₋₆-alkyl, and R⁴ has the meaning set forth above. A further object of the present invention is to provide compounds which are useful for preparing a medicament for treating conditions in mammals, including a human, sensitive to an excitatory amino acid. Said object is achieved by using an indole-2,3-dione-3-oxime compound having the formula wherein R¹ is hydrogen, C₁₋₆-alkyl which may be branched, C₃₋₇-cycloalkyl, benzyl, phenyl acyl, hydroxy, C₁₋₆-alkoxy, CH₂CO₂R' wherein R' is hydrogen or C₁₋₆-alkyl which may be branched, CH₂CN, CH₂CONR IV R V wherein R IV and R V independently are hydrogen or C₁₋₆-alkyl, or CH₂C(=NOH)NH₂; R² is hydrogen, benzyl, C₁₋₆-alkyl which may be branched, or C₃₋₇-cycloalkyl; R⁵ is NO₂, F, CF₃, SO₂NR''R''' wherein R'' and R''' independently are hydrogen or C₁₋₆-alkyl, or CN; and R⁴, R⁶, R⁷ independently are hydrogen, C₁₋₆-alkyl which may be branched, phenyl, halogen, C₁₋₆-alkoxy, NO₂, CN, SO₂NR''R''' wherein R'' and R''' independently are hydrogen or C₁₋₆-alkyl, or CF₃, or R⁶ and R⁷ together form an additional 4 to 7 membered ring which may be aromatic or partial saturated and which may be substituted with halogen, NO₂, CF₃, CN, SO₂NR''R''' wherein R'' and R''' independently are hydrogen or C₁₋₆-alkyl, and R⁴ has the meaning set forth above, for the preparation of a medicament useful in the treatment of conditions sensitive to an excitatory amino acid. In a preferred embodiment a compound is used wherein at least one of R⁴, R⁵, R⁶ and R⁷ is NO₂, CF₃, CN, SO₂NR''R''', or halogen and R¹, R², R⁴, R⁵, R⁶, R⁷, R'', and R''' otherwise have the meanings set forth in claim 1. In a further preferred embodiment a compound is used wherein R⁵ is NO₂, F, CF₃, or CN. In a method of antagonizing the biological effects of an excitatory amino acid the compound is administered in the form of a pharmaceutical composition thereof, in which it is present together with a pharmaceutically acceptable carrier or diluent. Preferred compounds have the formula wherein R¹ is C₁₋₆-alkyl which may be branched, C₃₋₇-cycloalkyl, benzyl, acyl, hydroxy, C₁₋₆-alkoxy, CH₂CO₂R' wherein R' is hydrogen or C₁₋₆-alkyl which may be branched, CH₂CN, CH₂CONR IV R V wherein R IV and R V independently are hydrogen or C₁₋₆-alkyl, or CH₂C(=NOH)NH₂; R² is hydrogen, benzyl, C₁₋₆-alkyl which may be branched, or C₃₋₇-cycloalkyl; R⁵ is NO₂, F, CF₃, SO₂NR''R''' wherein R'' and R''' independently are hydrogen or C₁₋₆-alkyl, or CN; and R⁴, R⁶, R⁷ independently are hydrogen, C₁₋₆-alkyl which may be branched, phenyl, halogen, C₁₋₆-alkoxy, NO₂, CN, SO₂NR''R''' wherein R'' and R''' independently are hydrogen or C₁₋₆-alkyl, or CF₃, or R⁶ and R⁷ together form an additional 4 to 7 membered ring which may be aromatic or partial saturated and which may be substituted with halogen, NO₂, CF₃, CN, SO₂NR''R''' wherein R'' and R''' independently are hydrogen or C₁₋₆-alkyl, and R⁴ has the meaning set forth above, Further preferred compounds have the formula wherein R¹ is hydrogen, R² is hydrogen, benzyl, C₁₋₆-alkyl which may be branched, or C₃₋₇-cycloalkyl; R⁵ is NO₂, F, CF₃, SO₂NR''R''' wherein R'' and R''' independently are hydrogen or C₁₋₆-alkyl, or CN; and R⁴, R⁶, R⁷ independently are hydrogen, C₁₋₆-alkyl which may be branched, phenyl, halogen, C₁₋₆-alkoxy, NO₂, CN, SO₂NR''R''' wherein R'' and R''' independently are hydrogen or C₁₋₆-alkyl, or CF₃, or R⁶ and R⁷ together form an additional 4 to 7 membered ring which may be aromatic or partial saturated and which may be substituted with halogen, NO₂, CF₃, CN, SO₂NR''R''' wherein R'' and R''' independently are hydrogen or C₁₋₆-alkyl, and R⁴ has the meaning set forth above; and that R⁵ is different from NO₂ and F when R¹, R⁴, R⁶ and R⁷ are hydrogen and R² is hydrogen or benzyl; and that R⁵ is different from NO₂ when R¹, R², R⁴ and R⁶ are hydrogen and R⁷ is NO₂. In a further preferred compound R⁴ and R⁵ independently are hydrogen, F, NO₂, CN, CF₃, or SO₂NR''R''' wherein R'' and R''' independently are hydrogen or C₁₋₆-alkyl, and wherein R⁶ and R⁷ together form an additional 4 to 7 membered ring which may be aromatic or partial saturated and which may be substituted with halogen, NO₂, CF₃, CN, SO₂NR''R''' wherein R'' and R''' independently are hydrogen or C₁₋₆-alkyl. In a further preferred compound as above the additional ring formed by R⁶ and R⁷ is substituted with halogen, NO₂, CF₃, CN or SO₂NR''R''' wherein R'' and R''' independently are hydrogen or C₁₋₆-alkyl. Particularly preferred compounds are 5-nitro-1H-benz[g]indole-2,3-dione-3-oxime; 5,7-dinitro-1-methyl-1H-indole-2,3-dione-3-(0-methyloxime); and 5-nitro-1H-6,7,8,9-tetrahydro-benz[g]indole-2,3-dione -3-oxime. Further it is provided a method of preparing a compound having the formula wherein R¹ is hydrogen, C₁₋₆-alkyl which may be branched, C₃₋₇-cycloalkyl, benzyl, acyl, hydroxy, C₁₋₆-alkoxy, CH₂CO₂R' wherein R' is hydrogen or C₁₋₆-alkyl which may be branched, CH₂CN, CH₂CONR IV R V wherein R IV and R V independently are hydrogen or C₁₋₆-alkyl, or CH₂C(=NOH)NH₂; R² is hydrogen, benzyl, C₁₋₆-alkyl which may be branched, or C₃₋₇-cycloalkyl; R⁵ is NO₂, F, CF₃, SO₂NR''R''' wherein R'' and R''' independently are hydrogen or C₁₋₆-alkyl, or CN; and R⁴, R⁶, R⁷ independently are hydrogen, C₁₋₆-alkyl which may be branched, phenyl, halogen, C₁₋₆-alkoxy, NO₂, SO₂NR''R''' wherein R'' and R''' independently are hydrogen or C₁₋₆-alkyl, CN, or CF₃, or R⁶ and R⁷ together form an additional 4 to 7 membered ring which may be aromatic or partial saturated and which may be substituted with halogen, NO₂, CF₃, CN, SO₂NR''R''' wherein R'' and R''' independently are hydrogen or C₁₋₆-alkyl, and R⁴ has the meaning set forth above; and that R⁵ is different from NO₂ and F when R¹, R⁴, R⁶ and R⁷ are hydrogen and R² is hydrogen or benzyl; and that R⁵ is different from NO₂ when R¹, R² R⁴ and R⁶ are hydrogen and R⁷ is NO₂, comprising the step of reacting a compound of the formula wherein R¹, R⁴, R⁵, R⁶ and R⁷ have the meanings set forth above, with a compound having the formula NH₂OR², wherein R² has the meaning set forth above. In preferred compounds used for preparing the medicament at least one of R⁴, R⁵, R⁶ or R⁷ is an electron withdrawing substituent such as NO₂, CF₃, CN, SO₂NR''R''', or halogen and R¹, R², R⁴, R⁵, R⁶, R⁷, R'' and R''' otherwise have the meanings set forth above. Preferred compounds to be employed according to the invention and preferred compounds according to the invention per se are for example: 5,7-dinitro-1-methyl-1H-indole-2,3-dione-3-(O-methyloxime) 5-bromo-7-nitro-1H-indole-2,3-dione-3-oxime, 5,7-dinitro-1-methyl-1H-indole-2,3-dione-3-oxime, 5-nitro-1H-benz[g]indole-2,3-dione-3-oxime, 5-nitro-1H-6,7,8,9-tetrahydro-benz[g]indole-2,3-dione-3-oxime. Biological Activity The compounds of the invention exhibit valuable biological properties because of their strong excitatory amino acid (EAA) (glycine, glutamate, quisqualate, ATPA, AMPA, kainate, NMDA) antagonizing properties. For example compounds of the invention exhibit strong pharmacological in vivo ATPA and quisqualate antagonizing effects demonstrating their utility as novel orally-bioavailable excitatory amino acid antagonists, which makes them useful in the treatment of for example excitatory amino acid dependent psychosis, excitatory amino acid dependent anoxia, excitatory amino acid dependent ischemia, excitatory amino acid dependent convulsions, and excitatory amino acid dependent migraine. Compounds of the invention will inhibit ATPA-induced rigidity and quisqualate or NMDA-induced convulsions with an ED₅₀ in the range of 0.1-10.0 mg/kg. Examples of such compounds are 5,7-dinitro-1-methyl-1H-indole-2,3-dione-3-(O-methyloxime) and 5,7-dinitro-1-(ethoxy carbonyl methyl)-1H-indole-2,3-dione-3-(0-methyloxime). Compounds of the invention show potent in vitro affinity for the glutamate subreceptors kainate, quisqualate and glycine receptors. These properties make the compounds useful in the treatment of human malfunctions related to the excitatory amino acids (EAA). For example some compounds of the invention exhibit binding at the ³H-kainate, ³H-AMPA and/or ³H-glycine binding sites with IC₅₀ in the range of 10-100 µM. Examples of such compounds are for example 5-bromo-7-nitro-1H-indole-2,3-dione-3-oxime, 5-nitro-1H-indole-2,3-dione-3-oxime, 5,7-dinitro-1H-indole-2,3-dione-3-oxime, 5,7-dinitro-1-methyl-1H-indole-2,3-dione-3-oxime, 1H-benz[g]indole-2,3-dione-3-oxime, 5-nitro-1H-benz[g]indole-2,3-dione-3-oxime, and 5-nitro-1H-6,7,8,9-tetrahydro-benz[g]indole-2,3-dione-3-oxime. Also the compounds of the invention as a secondary result of their EAA-antagonizing properties have been found to antagonize cocaine-induced hypermotility. For example the most potent compounds of the invention have been found to have an ED₅₀ in the range of 0.5-1.0 mg/kg in this test when administered orally. An example of such a compound is 5,7-dinitro-1-methyl-1H-indole-2,3-dione-3-(O-methyloxime). Furthermore it has been found that some of the compounds of the invention are metabolites of other compounds of the invention and that the metabolites exhibit biological activity in the same range or are even more potent than the precursor compounds or the invention. Accordingly both such parent or precursor compounds and such metabolites fall within the scope or the invention. Some of the compounds named in the foregoing will be recognized as metabolites of precursor compounds named in the foregoing, and vise versa. Such metabolites are for example: N-dealkylated derivatives, 1-N-hydroxyalkyl derivatives, 1-N-hydroxy derivatives, 1-N-oxide derivatives, O-dealkylated derivatives, pyrrolo ring opened hydrolyzed derivatives, pyrrolo ring opened hydrolyzed and decarboxylated derivatives as well as combinations of such metabolisation reactions. Biological testing The above mentioned tests are performed as described in more detail below and are based upon the principles also described hereinafter. ATPA-induced rigidity The selective quisqualate receptor agonist ATPA induces rigidity in female NMRI mice at doses between 3 and 15 mg/kg and clonic-tonic seizures and death, probably due to respiratory arrest, at doses between 15 and 40 mg/kg after intravenous (i.v.) administration. Method ATPA ((RS)-α-amino-3-hydroxy-5-tert-butyl-4-isoxazolepropionic acid) was dissolved in distilled water and test compound was dissolved in a polyoxyl 40 hydrogenated castor oil (5% Cremophor RH™ 40 (BASF)). Test compound was administered either i.v. 5, 30 or 120 min before or p.o. 30 min before an i.v. administration of 15 mg/kg of ATPA to 8 female NMRI mice per dose and the number of mice experiencing rigidity 5 min later was noted. An ED₅₀ value was calculated from at least three doses of test compound as the dose inhibiting 50% of the mice from having rigidity. Quisqualate-induced clonic seizures Quisqualate given icv (intracerebroventricular) to DBA/2 mice induces clonic seizures which can be inhibited by both NMDA and non-NMDA receptor antagonists after i.v. administration. Method Test compound was given i.v. 5 min before a 20 µg icv administration of quisqualate to 10 male DBA/2 mice (weighing 10-12 g) per dose. The number of mice experiencing clonic seizures within the next 2 min was noted. An ED₅₀ value was calculated as the dose inhibiting 50% of the mice from having clonic seizures. NMDA-induced clonic seizures NMDA give icv to NMRI mice induces clonic seizures which can be inhibited by NMDA receptor antagonists. Method Test compound was given i.v. 5 min before a 0.5 µg icv administration of NMDA to 10 male NMRI mice per dose. The number of mice experiencing clonic seizures within the next 2 min was noted. An ED₅₀ value was calculated as the dose inhibiting 50% of the mice from having clonic seizures. Cocaine-induced hypermotility Quisqualate and kainate administered locally induce an increase in dopamine release in nucleus accumbens and nucleus caudatus accompanied by stereotype behaviour such as hyperlocomotion, rearing, sniffing and grooming. These effects can be inhibited by selective quisqualate antagonists administered locally by the micro-dialyses method. Also the dopamine uptake inhibitor cocaine administered s.c. induce hypermotility which can be inhibited by an administration of the glutamate antagonist GDEE into nucleus accumbens. For these reasons (and others) it has been concluded that non-NMDA receptors regulate the release of dopamine in nucleus accumbens and that non-NMDA receptor antagonists can alleviate the symptoms of psychosis. Method Test compound was administered orally at doses of 0.1, 1, 10 and 30 mg/kg 30 min before the administration of 25 mg/kg cocaine i.p. to female NMRI mice and the locomotor activity of 2 mice per box was measured for the next 2 hours by use of 8 infrared photobeams per box. The mice had been adapted to the box for at least 16 hours to avoid exploratory motility (neophobia). The quisqualate binding assay was performed as described by T. Honoré et al., Neuroscience Letters 54 , 27-32 (1985). The kainate binding assay was performed as described by T. Honoré et al., Neuroscience Letters 65 , 47-52 (1986). The glycine binding assay was performed as described by W. Frost White et al., Journal of Neurochemistry 53(2) , 503-512 (1989). Pharmaceutical Compositions The compounds of the invention, together with a conventional adjuvant, carrier, or diluent, may be placed into the form of pharmaceutical compositions and unit dosages thereof, and in such form may be employed as solids, such as tablets or filled capsules, or liquids such as solutions, suspensions, emulsions, elixirs, or capsules filled with the same, all for oral use, in the form of suppositories for rectal administration; or in the form of sterile injectable solutions for parenteral (including subcutaneous) use. Such pharmaceutical compositions and unit dosage forms thereof may comprise conventional ingredients in conventional proportions, with or without additional active compounds or principles, and such unit dosage forms may contain any suitable effective amount of the active ingredient commensurate with the intended daily dosage range to be employed. Tablets containing ten (10) milligrams of active ingredients or, more broadly, 0.1 to one hundred (100) milligrams, per tablet, are accordingly suitable representative unit dosage forms. Solid forms of pharmaceutical compositions for p.o. administration and injectable solutions are preferred. Method of Treating The compounds of this invention are extremely useful in the treatment of central nervous system disorders related to their biological activity. The compounds of this invention may accordingly be administered to a subject, including a human, in need of treatment, alleviation, or elimination of an indication associated with the biological activity of the compounds. This includes especially excitatory amino acid dependent psychosis, excitatory amino acid dependent anoxia, excitatory amino acid dependent ischemia, excitatory amino acid dependent convulsions and excitatory amino acid dependent migraine. Suitable dosage ranges are 0.1 to 1000 milligrams daily, 10-500 milligrams daily, and especially 30-100 milligrams daily, dependent as usual upon the exact mode of administration, Form in which administered, the indication toward which the administration is directed, the subject involved and the body weight of the subject involved, and further the preference and experience of the physician or veterinarian in charge. Chemical Examples Some compounds of the invention are old, and others are novel chemical entities. In any-way the compounds of the invention may be prepared according to chemical methods which are well known. Example 1 a) 1-phenyl-1H-indole-2,3-dione. To a stirred solution of diphenylamine (3.2 g, 20 mmol) and 4-dimethylaminopyridine (10 mg) in chloroform (50 ml) was dropwise added oxalylchloride (3 ml). The resulting mixture was refluxed for 5 hours, whereafter it was cooled to room temperature and evaporated in vacuo. The residue (oil) was redissolved in methylene chloride (50 ml) and dry AlCl₃ (3 g) was added. Stirring at room temperature was continued for 30 hours, whereafter ethanol (10 ml) followed by water (100 ml) were added. The organic phase was washed with saturated Na₂CO₃, dried over Na₂SO₄ and evaporated. The crystalline residue was stirred in ether (40 ml) and the product was filtered off. Yield: 2.65 g orange crystals, M.p. 139-141°C, litt. 138°C. b) The following 1H-indole-2,3-diones were prepared according to known literature procedures. 1) Organic Synthesis Col Vol. I p. 327. 2) Martinet, J.: Compt. Rend. 166, 851, 1918. 4,6-ditrifluoromethyl-1H-indole-2,3-dione 1) , M.p. 162-165°C. 1H-benz[g]indole-2,3-dione 2) , M.p. 242-245°C. 7-trifluoromethyl-1H-indole-2,3-dione 1) , M.p. 181-183°C. 1H-6,7,8,9-tetrahydro-benz[g]indole-2,3-dione, M.p. 224-226°C. 6-methoxy-1H-indole-2,3-dione, M.p. >310°C. 7-trifluoromethyl-1H-indole-2,3-dione, M.p. 180-184°C. c) 1-methyl-5-nitro-7-trifluoromethyl-1H-indole-2,3-dione. To a stirred 10°C warm solution of KNO₃ (0.5 g) in 10 ml of conc. H₂SO₄ was dropwise added a solution of 1-methyl-7-trifluoromethyl-1H-indole-2,3-dione in 10 ml of conc. H₂SO₄. The addition was completed after 10 min, whereafter stirring was continued for 15 min at room temperature. The reaction mixture was poured on ice whereby the title compound precipitated as yellow crystals. The crystals were collected by filtration and washed with water. M.p. 168-169°C. In a similar manner to c), the following nitro compounds were prepared: 5-nitro-1H-6,7,8,9-tetrahydro-benz[g]indole-2,3-dione, M.p. 232-236°C. 5-nitro-1-methyl-1H-benz[g]indole-2,3-dione, M.p. 255-258°C. d) 5,7-dinitro-1-methyl-1H-indole-2,3-dione. To a stirred solution of 5,7-dinitro-1H-indole-2,3-dione (1.2 g) in dry dimethylformamide (20 ml) was added sodium hydride (0.24 g 55% in mineral oil). After the hydrogen evolution had ceased methyl iodide (0.37 ml) was added. Stirring at room temperature was continued for 2 hours, whereafter the crude product was precipitated as an oil by addition of water (100 ml) to the reaction mixture. The oil crystallized upon treatment with ether/pentane, M.p. 154-157°C. In a similar manner to d), the following 1-alkyl- or 1-benzyl-1H-indole-2,3-diones were prepared. 5,7-dinitro-1-ethyl-1H-indole-2,3-dione, M.p. 135-140°C. 5-bromo-1-methyl-1H-indole-2,3-dione, M.p. 157-160°C. 1H-1-methyl-6,7,8,9-tetrahydro-benz[g]indole-2,3-dione, M.p. 157-160°C. 5,7-dibromo-1-methyl-1H-indole-2,3-dione, M.p. 170-173°C. 5,6-dichloro-1-methyl-1H-indole-2,3-dione, M.p. 180-184°C. 4,5-dichloro-1-methyl-1H-indole-2,3-dione, M.p. 237-239°C. 1-methyl-5-nitro-1H-indole-2,3-dione, M.p. 196-199°C. 1-benzyl-5,7-dinitro-1H-indole-2,3-dione, M.p. 127-131°C. 4,6-ditrifluoromethyl-1-methyl-1H-indole, M.p. 93-94°C. 1-methyl-7-trifluoromethyl-1H-indole-2,3-dione, M.p. 120-122°C. 6-methoxy-1-methyl-1H-indole-2,3-dione, M.p. 175-178°C. 5,7-dinitro-1-(ethoxycarbonylmethyl)-1H-indole-2,3-dione, (oil). 1-methyl-1H-benz[g]indole-2,3-dione, M.p. 122-126°C. 1-(ethoxycarbonylmethyl)-1H-indole-2,3-dione, M.p. 115-119°C. 5,7-dibromo-1-(ethoxycarbonylmethyl)-1H-indole-2,3-dione, M.p. 97-102°C. 1-methyl-1H-6,7,8,9-tetrahydrobenz[g]indole-2,3-dione, M.p. 160-165°C. Example 2 5,7-dinitro-1-methyl-1H-indole-2,3-dione-3-(O-methyloxime). 5,7-dinitro-1-methyl-1H-indole-2,3-dione (0.4 g), O-methyl-hydroxylamine, hydrochloride (0.16 g) and sodium carbonate (0.2 g) was stirred at room temperature in ethanol (5 ml) for one hour, whereafter acetic acid (0.5 ml) followed by water (50 ml) were added. The mixture was cooled on ice and the crystalline product was obtained by filtration, M.p. 145-151°C. The following O-alkyloximes were prepared in a similar manner starting from the appropriate indole-2,3-diones. 5,7-dinitro-1H-indole-2,3-dione-3-(O-methyloxime), M.p. 236-239°C. 5,7-dinitro-1-ethyl-1H-indole-2,3-dione-3-(O-methyloxime), M.p. 156-159°C. 5-nitro-3-(O-methyloxime)-1H-indole-2,3-dione, M.p. 293-295°C. 1-phenyl-1H-indole-2,3-dione-3-(O-methyloxime), M.p. 151-153°C. 1H-indole-2,3-dione-3-(O-methyloxime), M.p. 168-171°C. 5,7-dibromo-1-methyl-1H-indole-2,3-dione-3-(O-methyloxime), M.p. 170-172°C. 5,7-dibromo-1H-indole-2,3-dione-3-(O-methyloxime), M.p. 279°C (decomp.). 1-methyl-5-nitro-1H-indole-2,3-dione-3-(O-methyloxime), M.p. 167-170°C. 5,6-dichloro-1-methyl-1H-indole-2,3-dione-3-(O-methyloxime), M.p. 202-204°C. 4,5-dichloro-1-methyl-1H-indole-2,3-dione-3-(O-methyloxime), M.p. 180-183°C. 5,7-dinitro-1-benzyl-1H-indole-2,3-dione-3-(O-methyloxime), M.p. 181-185°C. 4,5-ditrifluoromethyl-1-methyl-1H-indole-2,3-dione-3-(O-methyloxime), M.p. 99-100°C. 5-nitro-7-trifluoromethyl-1-methyl-1H-indole-2,3-dione-3-(O-methyloxime), M.p. 160-161°C. 5-nitro-7-trifluoromethyl-1H-indole-2,3-dione-3-(O-methyloxime), M.p. 225-228°C. 5,7-dinitro-6-methoxy-1-methyl-1H-indole-2,3-dione-3-(O-methyloxime), M.p. 145-148°C. 5,7-dinitro-1-(O-ethylcarboxymethyl)-1H-indole-2,3-dione-3-(O-methyloxime), M.p. 115-117°C. 5-nitro-1-methyl-1H-benz[g]indole-2,3-dione-3-(O-methyloxime), M.p. 255-258°C. 5-bromo-1-(ethoxycarbonylmethyl)-1H-indole-2,3-dione-3-(O-methyloxime), M.p. 201-204°C. 5,7-dibromo-1-(ethoxycarbonylmethyl)-1H-indole-2,3-dione-3-(O-methyloxime), M.p. 137-138°C. 5-methyl-1-(methoxycarbonylmethyl)-1H-indole-2,3-dione-3-(O-methyloxime), M.p. 127-131°C. 5-nitro-1-methyl-1H-6,7,8,9-tetrahydro-benz[g]indole-2,3-dione-3-(O-methyloxime), M.p. 220-224°C. Substitution of O-methyl-hydroxylamine hydrochloride in the process by hydroxylamine hydrochloride, afforded the following oximes. 1H-benz[g]indole-2,3-dione-3-oxime, M.p. 248-250°C. 5,7-dinitro-1-methyl-1H-indole-2,3-dione-3-oxime, M.p. 244°C (decomp.). 5,7-dibromo-1H-indole-2,3-dione-3-oxime, M.p. 240-242°C. 5-bromo-1-methyl-1H-indole-2,3-dione-3-oxime, M.p. 213-215°C. 5,7-dinitro-1H-indole-2,3-dione-3-oxime, M.p. 240-242°C. 5-bromo-7-nitro-1H-indole-2,3-dione-3-oxime, M.p. 254-256°C. 5-bromo-1H-indole-2,3-dione-3-oxime, M.p. 250-251°C. 5-nitro-1H-indole-2,3-dione-3-oxime, M.p. 243-245°C. 5-methyl-1H-indole-2,3-dione-3-oxime, M.p. 203-206°C. 1H-indole-2,3-dione-3-oxime, M.p. 234-236°C. 1-methyl-6,7,8,9-tetrahydro-1H-benz[g]indole-2,3-dione-3-oxime, M.p. 230-232°C. 5,6-dichloro-1-methyl-1H-indole-2,3-dione-3-oxime, M.p. 232-236°C. 4-phenyl-7-methoxy-1H-indole-2,3-dione-3-oxime M.p. 201-204°C. 4,5-dichloro-1H-indole-2,3-dione-3-oxime, M.p. 245-247°C. 1-phenyl-1H-indole-2,3-dione-3-oxime, M.p. 166-170°C. 4,5-dichloro-1-methyl-1H-indole-2,3-dione-3-oxime, M.p. 140-142°C. 5-nitro-1H-benz[g]indole-2,3-dione-3-oxime, M.p. 197-199°C. 5-nitro-7-trifluoromethyl-1-methyl-1H-indole-2,3-dione-3-oxime, M.p. 204-205°C. 5-nitro-7-trifluoromethyl-1H-indole-2,3-dione-3-oxime, M.p. 230-232°C. 5-nitro-1H-6,7,8,9-tetrahydro-benz[g]indole-2,3-dione-3-oxime, M.p. 205-210°C. 5-fluoro-7-nitro-1H-indole-2,3-dione-3-oxime, M.p. 260-262°C. 5,7-dinitro-1-(ethoxycarbonylmethyl)-1H-indole-2,3-dione-3-oxime, M.p. 217-220°C. 1-(ethoxycarbonylmethyl)-1H-indole-2,3-dione-3-oxime, M.p. 183-185°C. 5-bromo-1-(ethoxycarbonylmethyl)-1H-indole-2,3-dione-3-oxime, M.p. 178-181°C. 5,7-dinitro-1H-indole-2,3-indole-2,3-dione-3-oxime, M.p. 195-197°C. Substitution ox hydroxylamine hydrochloride in the process by O-benzylhydroxylamine, afforded the following compounds. 5,7-dinitro-1H-indole-2,3-dione-3-(O-benzyloxime), M.p. 197-199°C. 5,7-dinitro-1H-1-benzyl-indole-2,3-dione-3-(O-benzyloxime), M.p. 148-150°C. 5,7-dinitro-1-methyl-1H-indole-2,3-dione-3-(O-benzyloxime), M.p. 120-125°C. 5,7-dinitro-1-(ethoxycarbonylmethyl)-1H-indole-2,3-dione-3-(O-benzyloxime), M.p. 100-102°C. 5-nitro-1-(ethoxycarbonylmethyl)-1H-indole-2,3-dione-3-(O-benzyloxime), M.p. 185-187°C. The following compounds were prepared according to literature procedures: 1-methoxy-1H-indole-2,3-dione-3-oxime, M.p. 166-168°C. 1-acetyl-5-bromo-1H-indole-2,3-dione, M.p. 133-135°C. 1-hydroxy-1H-indole-2,3-dione-3-oxime, M.p. 217-221°C. Example 3 a) 1-carboxymethyl-1H-indole-2,3-dione. 8.39 g (36 mmol) 1-(ethoxycarbonylmethyl)-1H-indole-2,3-dione and 4N NaOH (10 ml, 40 mmol) were dissolved in 30 ml H₂O and 10 ml absolute ethanol and the mixture was heated at reflux for 30 minutes. The reaction mixture was cooled and added excess hydrochloric acid. The precipitate was isolated. Yield of title compound is 6.2 g. b) 1-chlorocarbonylmethyl-1H-indole-2,3-dione. 1 g of the product prepared under a) was suspended in toluene (10 ml) and SOCl₂ (1.0 ml, 13.78 mmol) was added. The mixture was stirred at RT for 2 hours and additionally at 70°C for 30 minutes and thereafter at reflux for 1 hour. The reaction mixture was stirred at RT overnight whereafter the precipitated yellow crystals were isolated and washed with toluene. Yield of title compound was 1.3 g including solvent content. c) 1-aminocarbonylmethyl-1H-indole-2,3-dione. The product prepared under b) was dissolved in dry THF (50 ml) and to the solution was added liquid NH₃. The resulting mixture was stirred overnight at RT. The precipitated orange crystals were isolated and were washed with water. Yield or title compound was 0.46 g. d) 1-cyanomethyl-1H-indole-2,3-dione. Triphenylphosphine (0.75 g, 2.84 mmol) was dissolved in methylenechloride and to the solution was added dropwise to Br₂ (0.15 ml, 2.84 mmol) in methyleneohloride (20 ml). To this mixture the product prepared under c) was added, and thereafter triethylamine (0.8 ml, 5.63 mmol) was added dropwise. The mixture was stirred for 30 minutes. The reaction mixture was evaporated in vacuo and the residue was taken up in ether. The precipitate from this mixture was filtered off and the ether solution was washed with water and dried (MgSO₄). The ether solution was evaporated in vacuo and the residue was washed with isopropanol. Yield of title compound was 0.11 g. M.p. 125-128°C. e) 1-(acetamideoxime-2-yl)-1H-indole-2,3-dione-3-oxime. The product prepared under d) (90 mg, 0.48 mmol), hydroxylamine hydrochloride (70 mg, 1.06 mmol), potassium carbonate (150 mg, 1.06 mmol) and methanol (10 ml) were mixed and the mixture was stirred at RT overnight. The reaction mixture was evaporated in vacuo . The residue was washed with water containing small amounts of acetic acid. Yield of title compound was 70 mg. M.p. 227-229°C. It is thus seen that the present invention provides a new and convenient process for the production of indole-2,3-dione-3-oxime compounds, certain novel indole-2,3-dione-3-oxime compounds which are useful as excitatory amino acid antagonists, pharmaceutical-compositions useful as excitatory amino acid antagonists comprising certain indole-2,3-dione-3-oxime compounds, and a method of antagonizing the biological effects of excitatory amino acids in a subject in need thereof comprising the step of administering certain indole-2,3-dione-3-oxime compounds or a pharmaceutical composition comprising the same together with a pharmaceutically-acceptable diluent or carrier, all having the foregoing characteristics and advantages.

Claims: Claims for the following Contracting States : AT, BE, CH, LI, DE, DK, FR, GB, IT, LU, NL, SE A compound having the formula wherein R¹ is hydrogen, C₁₋₆-alkyl which may be branched, C₃₋₇-cyclo alkyl, benzyl, acyl, hydroxy, C₁₋₆-alkoxy, CH₂CO₂R' wherein R' is hydrogen or C₁₋₆-alkyl which may be branched, CH₂CN, CH₂CONR IV R V wherein R IV and R V independently are hydrogen or C₁₋₆-alkyl, or CH₂C(=NOH)NH₂; R² is hydrogen, benzyl, C₁₋₆-alkyl which may be branched, or C₃₋₇-cycloalkyl; R⁵ is NO₂, F, CF₃, SO₂NR''R''' wherein R'' and R''' independently are hydrogen or C₁₋₆-alkyl, or CN; and R⁴, R⁶, R⁷ independently are hydrogen, C₁₋₆-alkyl which may be branched, phenyl, halogen, C₁₋₆-alkoxy, NO₂, CN, SO₂NR''R''' wherein R'' and R''' independently are hydrogen or C₁₋₆-alkyl, or CF₃, or R⁶ and R⁷ together form an additional 4 to 7 membered ring which may be aromatic or partial saturated and which may be substituted with halogen, NO₂, CF₃, CN, SO₂NR''R''' wherein R'' and R''' independently are hydrogen or C₁₋₆-alkyl, and R⁴ has the meaning set forth above, with the proviso that R⁵ is different from NO₂ and F when R¹, R⁴, R⁶ and R⁷ are hydrogen and R² is hydrogen or benzyl; and that R⁵ is different from NO₂ when R¹, R², R⁴ and R⁶ are hydrogen and R⁷ is NO₂. The compound according to claim 1 wherein R⁵ is F, NO₂, CN, CF₃, or SO₂NR''R''' wherein R'' and R''' independently are hydrogen or C₁₋₆-alkyl, and wherein R⁶ and R⁷ together form an additional 4 to 7 membered ring which may be aromatic or partial saturated and which may be substituted with halogen, NO₂, CF₃, CN, SO₂NR''R''' wherein R'' and R''' independently are hydrogen or C₁₋₆-alkyl. The compound according to claim 2 wherein the additional ring formed by R⁶ and R⁷ is substituted with halogen, NO₂, CF₃, CN or SO₂NR''R''' wherein R'' and R''' independently are hydrogen or C₁₋₆-alkyl. The compound according to Claim 1, which is 5-nitro-1H-benz[ g] -indole-2,3-dione-3-oxime. The compound according to Claim 1, which is 5,7-dinitro-1-methyl-1H-indole-2,3-dione-3-(0-methyloxime). The compound according to Claim 1, which is 5-nitro-1H-6,7,8,9-tetrahydro-benz[ g] indole-2,3-dione-3-oxime. A pharmaceutical composition comprising an effective excitatory amino acid antagonizing amount of a compound having the formula wherein R¹ is hydrogen, C₁₋₆-alkyl which may be branched, C₃₋₇-cyclo alkyl, benzyl, acyl, hydroxy, C₁₋₆-alkoxy, CH₂CO₂R' wherein R' is hydrogen or C₁₋₆-alkyl which may be branched, CH₂CN, CH₂CONR IV R V wherein R IV and R V independently are hydrogen or C₁₋₆-alkyl, or CH₂C(=NOH)NH₂; R² is hydrogen, benzyl, C₁₋₆-alkyl which may be branched, or C₃₋₇-cycloalkyl; R⁵ is NO₂, F, CF₃, SO₂NR''R''' wherein R'' and R''' independently are hydrogen or C₁₋₆-alkyl, or CN; and R⁴, R⁶, R⁷ independently are hydrogen, C₁₋₆-alkyl which may be branched, phenyl, halogen, C₁₋₆-alkoxy, NO₂, CN, SO₂NR''R''' wherein R'' and R''' independently are hydrogen or C₁₋₆-alkyl, or CF₃, or R⁶ and R⁷ together form an additional 4 to 7 membered ring which may be aromatic or partial saturated and which may be substituted with halogen, NO₂, CF₃, CN, SO₂NR''R''' wherein R'' and R''' independently are hydrogen or C₁₋₆-alkyl, and R⁴ has the meaning set forth above. A method of preparing the compound according to Claim 1, comprising the step of reacting a compound of the formula wherein R¹, R⁴, R⁵, R⁶, and R⁷ have the meaning set forth in Claim 1, with a compound having the formula NH₂OR², wherein R² has the meaning set forth in Claim 1. The use of an indole-2,3-dione-3-oxime compound having the formula wherein R¹ is hydrogen, C₁₋₆-alkyl which may be branched, C₃₋₇-cycloalkyl, benzyl, phenyl acyl, hydroxy, C₁₋₆-alkoxy, CH₂CO₂R' wherein R' is hydrogen or C₁₋₆-alkyl which may be branched, CH₂CN, CH₂CONR IV R V wherein R IV and R V independently are hydrogen or C₁₋₆-alkyl, or CH₂C(=NOH)NH₂; R² is hydrogen, benzyl, C₁₋₆-alkyl which may be branched, or C₃₋₇-cycloalkyl; R⁵ is NO₂, F, CF₃, SO₂NR''R''' wherein R'' and R''' independently are hydrogen or C₁₋₆-alkyl, or CN; and R⁴, R⁶, R⁷ independently are hydrogen, C₁₋₆-alkyl which may be branched, phenyl, halogen, C₁₋₆-alkoxy, NO₂, CN, SO₂NR''R''' wherein R'' and R''' independently are hydrogen or C₁₋₆-alkyl, or CF₃, or R⁶ and R⁷ together form an additional 4 to 7 membered ring which may be aromatic or partial saturated and which may be substituted with halogen, NO₂, CF₃, CN, SO₂NR''R''' wherein R'' and R''' independently are hydrogen or C₁₋₆-alkyl, and R⁴ has the meaning set forth above, for the preparation of a medicament useful in the treatment of conditions sensitive to an excitatory amino acid. The use according to Claim 9 wherein at least one of R⁴, R⁵, R⁶ and R⁷ is NO₂, CF₃, CN, SO₂NR''R''', or halogen and R¹, R², R⁴, R⁵, R⁶, R⁷, R'', and R''' otherwise have the meanings set forth in claim 1. The use according to Claim 9 wherein R⁵ is NO₂, F, CF₃, or CN. Claims for the following Contracting State : ES A method for preparing a compound having the formula wherein R¹ is hydrogen, C₁₋₆-alkyl which may be branched, C₃₋₇-cyclo alkyl, benzyl, acyl, hydroxy, C₁₋₆-alkoxy, CH₂CO₂R' wherein R' is hydrogen or C₁₋₆-alkyl which may be branched, CH₂CN, CH₂CONR IV R V wherein R IV and R V independently are hydrogen or C₁₋₆-alkyl, or CH₂C(=NOH)NH₂; R² is hydrogen, benzyl, C₁₋₆-alkyl which may be branched, or C₃₋₇-cycloalkyl; R⁵ is NO₂, F, CF₃, SO₂NR''R''' wherein R'' and R''' independently are hydrogen or C₁₋₆-alkyl or CN; and R⁴, R⁶, R⁷ independently are hydrogen, C₁₋₆-alkyl, which may be branched, phenyl, halogen, C₁₋₆-alkoxy, NO₂, CN, SO₂NR''R''' wherein R'' and R''' independently are hydrogen or C₁₋₆-alkyl, or CF₃, or R⁶ and R⁷ together form an additional 4 to 7 membered ring which may be aromatic or partial saturated and which may be substituted with halogen, NO₂, CF₃ CN, SO₂NR''R''' wherein R'' and R''' independently are hydrogen or C₁₋₆-alkyl, and R⁴ has the meaning set forth above, with the proviso that R⁵ is different from NO₂ and F when R¹, R⁴, R⁶ and R⁷ are hydrogen and R² is hydrogen or benzyl; and that R⁵ is different from NO₂ when R¹, R², R⁴ and R⁶ are hydrogen and R⁷ is NO₂, comprising the step of reacting a compound of the formula wherein R¹, R⁴, R⁵, R⁶, and R⁷ have the meaning set forth above, with a compound having the formula NH₂OR², wherein R² has the meaning as set forth above. The process according to claim 1, wherein R⁵ is F, NO₂, CN, CF₃, or SO₂NR''R''' wherein R'' and R''' independently are hydrogen or C₁₋₆-alkyl, and wherein R⁶ and R⁷ together form an additional 4 to 7 membered ring which may be aromatic or partial saturated and which may be substituted with halogen, NO₂, CF₃, CN, SO₂NR''R''' wherein R'' and R''' independently are hydrogen or C₁₋₆-alkyl. The process according to claim 2, wherein the additional ring formed by R⁶ and R⁷ is substituted with halogen, NO₂, CF₃, CN or SO₂NR''R''' wherein R'' and R''' independently are hydrogen or C₁₋₆-alkyl. The process according to claim 1, wherein the prepared compound is 5-nitro-1H-benz[ g] -indole-2,3-dione-3-oxime. The process according to claim 1, wherein the prepared compound is 5,7-dinitro-1-methyl-1H-indole-2,3-dione-3-(0-methyloxime). The process according to claim 1, wherein the prepared compound is 5-nitro-1H-6,7,8,9-tetrahydro-benz[ g] indole-2,3-dione-3-oxime. A process for preparing a pharmaceutical composition comprising an effective excitatory amino acid antagonizing amount of a compound having the formula wherein R¹ is hydrogen, C₁₋₆-alkyl which may be branched, C₃₋₇-cyclo alkyl, benzyl, acyl, hydroxy, C₁₋₆-alkoxy, CH₂CO₂R' wherein R' is hydrogen or C₁₋₆-alkyl which may be branched, CH₂CN, CH₂CONR IV R V wherein R IV and R V independently are hydrogen or C₁₋₆-alkyl, or CH₂C(=NOH)NH₂; R² is hydrogen, benzyl, C₁₋₆-alkyl which may be branched, or C₃₋₇-cycloalkyl; R⁵ is NO₂, F, CF₃, SO₂NR''R''' wherein R'' and R''' independently are hydrogen or C₁₋₆-alkyl or CN; and R⁴, R⁶ R⁷ independently are hydrogen, C₁₋₆-alkyl which may be branched, phenyl, halogen, C₁₋₆-alkoxy, NO₂, CN, SO₂NR''R''' wherein R'' and R''' independently are hydrogen or C₁₋₆-alkyl, or CF₃, or R⁶ and R⁷ together form an additional 4 to 7 membered ring which may be aromatic or partial saturated and which may be substituted with halogen, NO₂, CF₃, CN, SO₂NR''R''' wherein R'' and R''' independently are hydrogen or C₁₋₆-alkyl, and R⁴ has the meaning set forth above, by combining the compound with conventional additives in a manner known per se. Claims for the following Contracting State : GR A compound having the formula wherein R¹ is hydrogen, C₁₋₆-alkyl which may be branched, C₃₋₇-cyclo alkyl, benzyl, acyl, hydroxy, C₁₋₆-alkoxy, CH₂CO₂R' wherein R' is hydrogen or C₁₋₆-alkyl which may be branched, CH₂CN, CH₂CONR IV R V wherein R IV and R V independently are hydrogen or C₁₋₆-alkyl, or CH₂C(=NOH)NH₂; R² is hydrogen, benzyl, C₁₋₆-alkyl which may be branched, or C₃₋₇-cycloalkyl; R⁵ is NO₂, F, CF₃, SO₂NR''R''' wherein R'' and R''' independently are hydrogen or C₁₋₆-alkyl or CN; and R⁴, R⁶, R⁷ independently are hydrogen, C₁₋₆-alkyl, which may be branched, phenyl, halogen, C₁₋₆-alkoxy, NO₂, CN, SO₂NR''R''' wherein R'' and R''' independently are hydrogen or C₁₋₆-alkyl, or CF₃, or R⁶ and R⁷ together form an additional 4 to 7 membered ring which may be aromatic or partial saturated and which may be substituted with halogen, NO₂, CF₃ CN, SO₂NR''R''' wherein R'' and R''' independently are hydrogen or C₁₋₆-alkyl, and R⁴ has the meaning set forth above, with the proviso that R⁵ is different from NO₂ and F when R¹, R⁴, R⁶ and R⁷ are hydrogen and R² is hydrogen or benzyl; and that R⁵ is different from NO₂ when R¹, R², R⁴ and R⁶ are hydrogen and R⁷ is NO₂. The compound according to claim 1, wherein R⁵ is F, NO₂, CN, CF₃, or SO₂NR''R''' wherein R'' and R''' independently are hydrogen or C₁₋₆-alkyl, and wherein R⁶ and R⁷ together form an additional 4 to 7 membered ring which may be aromatic or partial saturated and which may be substituted with halogen, NO₂, CF₃, CN, SO₂NR''R''' wherein R'' and R''' independently are hydrogen or C₁₋₆-alkyl. The compound according to claim 2, wherein the additional ring formed by R⁶ and R⁷ is substituted with halogen, NO₂, CF₃, CN or SO₂NR''R''' wherein R'' and R''' independently are hydrogen or C₁₋₆-alkyl. The compound according to claim 1, which is 5-nitro-1H-benz[ g] -indole-2,3-dione-3-oxime. The compound according to claim 1, which is 5,7-dinitro-1-methyl-1H-indole-2,3-dione-3-(0-methyloxime). The compound according to claim 1, which is 5-nitro-1H-6,7,8,9-tetrahydro-benz[ g] indole-2,3-dione-3-oxime. A process for preparing a pharmaceutical composition comprising an effective excitatory amino acid antagonizing amount of a compound having the formula wherein R¹ is hydrogen, C₁₋₆-alkyl which may be branched, C₃₋₇-cyclo alkyl, benzyl, acyl, hydroxy, C₁₋₆-alkoxy, CH₂CO₂R' wherein R' is hydrogen or C₁₋₆-alkyl which may be branched, CH₂CN, CH₂CONR IV R V wherein R IV and R V independently are hydrogen or C₁₋₆-alkyl, or CH₂C(=NOH)NH₂; R² is hydrogen, benzyl, C₁₋₆-alkyl which may be branched, or C₃₋₇-cycloalkyl; R⁵ is NO₂, F, CF₃, SO₂NR''R''' wherein R'' and R''' independently are hydrogen or C₁₋₆-alkyl or CN; and R⁴, R⁶, R⁷ independently are hydrogen, C₁₋₆-alkyl which may be branched, phenyl, halogen, C₁₋₆-alkoxy, NO₂, CN, SO₂NR''R''' wherein R'' and R''' independently are hydrogen or C₁₋₆-alkyl, or CF₃, or R⁶ and R⁷ together form an additional 4 to 7 membered ring which may be aromatic or partial saturated and which may be substituted with halogen, NO₂, CF₃, CN, SO₂NR''R''' wherein R'' and R''' independently are hydrogen or C₁₋₆-alkyl, and R⁴ has the meaning set forth above by combining the compound with conventional additives in a manner known per se. A method of preparing the compound according to claim 1, comprising the step of reacting a compound of the formula wherein R¹, R⁴, R⁵, R⁶ and R⁷ have the meaning set forth in claim 1, with a compound having the formula NH₂OR², wherein R² has the meaning set forth in claim 1. The use of an indole-2,3-dione-3-oxime compound having the formula wherein R¹ is hydrogen, C₁₋₆-alkyl which may be branched, C₃₋₇-cycloalkyl, benzyl, phenyl, acyl, hydroxy, C₁₋₆-alkoxy, CH₂CO₂R' wherein R' is hydrogen or C₁₋₆-alkyl which may be branched, CH₂CN, CH₂CONR IV R V wherein R IV and R V independently are hydrogen or C₁₋₆-alkyl, or CH₂C(=NOH)NH₂; R² is hydrogen, benzyl, C₁₋₆-alkyl which may be branched, or C₃₋₇-cycloalkyl; R⁵ is NO₂, F, CF₃, SO₂NR''R''' wherein R'' and R''' independently are hydrogen or C₁₋₆-alkyl or CN; and R⁴, R⁶, R⁷ independently are hydrogen, C₁₋₆-alkyl which may be branched, phenyl, halogen, C₁₋₆-alkoxy, NO₂, CN, SO₂NR''R''' wherein R'' and R''' independently are hydrogen or C₁₋₆-alkyl, or CF₃, or R⁶ and R⁷ together form an additional 4 to 7 membered ring which may be aromatic or partial saturated and which may be substituted with halogen, NO₂, CF₃, CN, SO₂NR''R''' wherein R'' and R''' independently are hydrogen or C₁₋₆-alkyl, and R⁴ has the meaning set forth above, for the preparation of a medicament useful in the treatment of conditions sensitive to an excitatory amino acid. The use according to claim 9 wherein at least one of R⁴, R⁵, R⁶ and R⁷ is NO₂, CF₃, CN, SO₂NR''R''', or halogen and R¹, R², R⁴, R⁵, R⁶, R⁷, R'', and R''' otherwise have the meanings set forth in claim 1. The use according to claim 9 wherein R⁵ is NO₂, F, CF₃, or CN.

Inventors: DREJER JORGEN, JENSEN LEIF HELTH, WAETJEN FRANK, DREJER, JORGEN, JENSEN, LEIF HELTH, WAETJEN, FRANK, Wätjen, Frank 
Applicants: NEUROSEARCH AS, NEUROSEARCH A/S
Application year: 1990
Main classification: C07D209
IPC codes: A61K31, A61P25, C07D209, A61P43