GB1048104A - Pharmaceutical compositions containing 3,5-disubstituted pyrazoles - Google Patents

Abstract

3,5-Disubstituted pyrazoles of formula <FORM:1048104/C2/1> wherein R1 is alkyl and R2 is carboxyl, carbamoyl, alkoxycarbonyl, or alkyl monosubstituted carbamoyl, alkyl being C1 to C4, are prepared by reacting together hydrazine and an appropriate keto-acid; (i.e. a pyruvic or substituted pyruvic acid). The following examples illustrate this procedure: (1) Acetopyruvic acid and hydrazine sulphate are reacted in aqueous solution at 50 DEG C. to yield 3-carboxy-5-methyl pyrazole, which is purified by recrystallization from isopropanol-ethanol; (3) sodium ethylpropiopyruvate and hydrazine sulphate are reacted in aqueous sodium acetate solution at below 30 DEG C. to yield 3-ethoxycarbonyl-5-ethyl pyrazole. The latter is used to prepare 3-carboxy-5-ethyl -pyrazole, by further reaction with sodium hydroxide; (4) the product of Example 1 is converted to its sodium salt with sodium carbonate; also the following are said to be similarly obtainable: salts of K, Al, Ca, Mg, NH4, and procaine, N,N1-dibenzylethylenediamine, and diethanolamine; (5) sodium ethyl acetopyruvate and hydrazine sulphate are reacted in aqueous sodium acetate solution at 45 DEG C. to yield 3-ethoxycarbonyl-5-methylpyrazole; (6) the product of the latter example is used to prepare 3-carbamoyl-5-methyl pyrazole by further reaction with ammonium hydroxide at elevated temperature; (7) the product of Example (1) is dimerized by heating in thionyl chloride, and the dimer heated with 40% aqueous methylamine whereupon 3-Nmethylcarbamoyl - 5 - methyl pyrazole is produced. The preparation of the aforesaid substituted pyruvic acids is also illustrated in the following examples: (3) methyl ethyl ketone and sodium ethoxide, in ethanolic solution, are reacted at 15 DEG C., to yield sodium ethyl-propiopyruvate; (5) ethyl oxalate and acetone are refluxed with sodium ethoxide in ethanol to yield sodium ethyl acetopyruvate. The substituted pyrazoles are of use in pharmaceutical compositions (see Division A5).ALSO:Hypoglycemic compositions comprise a 3, 5-disubstituted pyrazole of formula <FORM:1048104/A5-A6/1> wherein R1 is alkyl, and R2 is carboxyl, alkoxycarbonyl, carbamoyl, or alkyl monosubstituted carbamoyl, alkyl being C1 to C4, or physiologically acceptable salts thereof, dispersed in a solid vehicle or in a liquid which is a non-solvent for the active ingredient. The compositions may be in unit dosage forms for oral or parenteral administration, such as tablets, pills, capsules, powders, wafers, cachets, granules, oral or sterile parenteral aqueous or non-aqueous dispersions including elixirs, or suppositories. Tablets and pills may be laminated to provide prolonged, delayed, or successive action; enteric coating materials employed may be shellac, shellac with cetyl alcohol, cellulose acetate phthalate, polymeric acids and particularly a styrenemaleic acid copolymer. Other optional ingredients of the compositions include conventional suspending and dispersing agents, solid excipients, surface active agents, preservatives, salts to effect isotonicity, oils, synthetic sweeteners, flavouring agents, dyes and other non-sugar containing ingredients. The compositions may further contain other active ingredients, such as other hypoglycemics, e.g. tolbutamide, chlorpropamide, phenformin HCl, mesoxalic acid, insulin, or nicotinic acid; utilizable potassium salts; hypocholesteremic agents; e.g. D-3, 5, 31-triiodothyronine, triiodothyropropionic acid, sodium L-or sodium D-thyroxine; glucocortiocoids, e.g. hydrocortisone, prednisolone, and 6a -methyl prednisolone; anticoagulants, e.g. heparin, 2-diphenyl acetyl-1, 3-indandione, polethylene sulphonate, and dicoumarol; vitamins, e.g. nicotinic acid, vitamin B12, ascorbic acid, or pyridoxine HCl; estrogens, e.g. estradiol; and androgens, e.g. testosterone; antibiotics, e.g. neomycin; analgesics such as aspirin; cholesterol metabolites such as a -phenyl-and a -p-biphenyl-butyric acid; lipotropic agents, e.g. choline and inositol; amino acids, e.g. taurine and glycine; plant sterols such as sitosterol; diuretics, such as ethoxazolamide or hydrochlorthiazide; anorectics such as amphetamine; and cardiovascular agents such as chlorisondamine chloride, hexamethonium chloride and pentaerythrital tetranitrate. Also mentioned are salts of the essential ingredient with a physiologically active base-i.e. diethanolamine, N,N1-dibenzylethylenediamine, or procaine. Examples include compositions for oral and parenteral use, and synthetic processes for preparing the inventive active ingredients, (see Division C2)