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United States Patent Office Patented May 16, 1967 2 3,320,312 the Preparation of the P-Acetylsulfonylurea Compounds

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United States Patent Office Patented May 16, 1967 2 3,320,312 the Preparation of the P-Acetylsulfonylurea Compounds 3,320,312 United States Patent Office Patented May 16, 1967 2 3,320,312 the preparation of the p-acetylsulfonylurea compounds. PHENY SULFONYL. CYCLO-AE EYE UREAS AND Suitable protecting groups include acyl and carbamate THE PREPARATION THEREOF groups, either of which can readily be removed by simple Max W. Sigal, Jr., and Arthur M. Van Arendonk, Indian hydrolysis to give the desired hydroxyl-containing sul apolis, Ind., assignors to Eli Lily and Company, n fonylurea. dianapolis, id., a corporation of indiana The novel compounds of this invention have hypogly No Drawing. Fied Apr. 28, 1960, Ser. No. 25,209 cenic properties which make them useful anti-diabetic 4. Claims. (C. 260-553) agents. Thus, for example, adequate regulation of the blood Sugar levels of diabetics can be secured by the oral This invention relates to certain novel N-substituted O administration of N-p-acetylphenylsulfonyl-N'-cyclohexyl phenylsulfonyl-N'-cyclo-alkylureas. urea in daily dosage amounts in the range of about 250 The compounds provided by this invention can be repre to about 1000 mg. Clinical tests have not shown any sented by the following formula: Serious side effects such as jaundice and hepatotoxicity which have resulted from the administration of certain 5 other oral hypoglycemic agents. The compounds of this invention preferably are ad wherein R is cyclohexyl or cycloheptyl, and X is ministered orally in one of the customary oral dosage - . forms, for example, compressed tablets or filled capsules, -C- or -CHOH which contain the desired amount of medicament to The compounds represented by the above formula 20 gether with the customary binders, fillers and other ex wherein X is a carbonyl grouping cipients. Illustratively, N- p - acetylphenylsulfonyl- N'- cyclohexylurea can be processed into tablets suitable for oral administration by the following procedure: 1424 g. (-C-) of the cyclohexylurea are mixed with 399 g. of starch, are preferably prepared by reacting p-acetylphenylsulfon 25 20 g. of granular gelatin, and 37 g. of magnesium stear amide with cyclohexylisocyanate or with cycloheptyliso ate, and the mixture is pressed into scored tablets, of cyanate in the presence of an alkaline carbonate. Com such size that each tablet contains 500 mg. of N-p-acetyl pounds of this invention represented by the above for phenylsulfonyl-N'-cyclohexylurea. This invention is further illustrated by the following mula wherein X is a secondary alcohol group 30 examples. (-CHOH-) EXAMPLE 1. are most readily prepared by hydrogenating the carbonyl group of the corresponding p-acetylphenylsulfonylcyclo Preparation of p-acetylbenzenesulfonamide alkylurea. 100 g. of p-aminoacetophenone were dissolved in a sol Also included within the scope of this invention are vent mixture containing 165 ml. of 12 N. hydrochloric the nontoxic, cationic salts of the above-mentioned N-sub acid and 165 ml. of glacial acetic acid. The mixture was stituted phenylsulfonyl-N'-cyclo-alkylureas. The salts cooled with stirring to about 0° C. A solution containing can be formed by reacting the phenylsulfonylurea with 56.2 g. of sodium nitrite and 175 ml. of water was added a suitable base or basic salt such as ammonium hydroxide, dropwise with stirring to the acidic solution while main potassium hydroxide, magnesium hydroxide, sodium car 40 taining the temperature below 5° C. After the addition bonate, and the like. Among the preferred nontoxic, had been completed, the acidic solution containing p cationic salts are the sodium, potassium, calcium, mag acetylphenyldiazonium chloride formed in the above re nesium, and ammonium salts. action was added dropwise with stirring to a mixture of Both the N-substituted phenylsulfonyl-N'-cyclo-alkyl 530 ml. of glacial acetic acid and 530 ml. of benzene ureas and their nontoxic, cationic salts are white, high which had been previously cooled, and the cooled solu melting solids. The ureas themselves are soluble in most tion saturated with sulfur dioxide and to which had been polar organic solvents, whereas the cationic salts are solu added 34 g. of cupric chloride dihydrate. After the ad ble in aqueous solvents. dition had been completed, the reaction mixture was The compounds of this invention can be prepared by stirred at about 40 C. for three hours, and was then methods other than the preferred methods disclosed above. poured into 3000 ml. of an ice-water mixture. The ben For example, an alternative procedure for the prepara zene layer containing p-acetylbenzenesulfonyl chloride tion of compounds represented by the above formula formed in the above reaction was separated, and the acidic wherein X is a carbonyl grouping, comprises the reaction aqueous phase was extracted twice with 250 ml. portions of p-acetylphenylsulfonamide with ethylchlorocarbonate of benzene. The benzene layers were combined, the com to form the corresponding urethane, which is in turn re 55 bined extracts were filtered, and the benzene was evapo acted with cyclohexyl or cycloheptyl amine to give the rated from the resulting filtrate in vacuo. The solid desired sulfonylurea. In addition, there are available the residue comprising p-acetylbenzenesulfonyl chloride was reaction of p-acetylphenylsulfonamide with cyclohexyl or dissolved in 100 ml. of dioxane, and the solution was cycloheptyl urethane, the reaction of p-acetylphenylsul added to 200 ml. of 14 percent aqueous ammonium hy fonylisocyanate with the cyclo-alkyl amine, as well as the 60 droxide. The resulting solution was stirred overnight at reaction of two molecules of p-acetylphenylsulfonamide ambient room temperature. The p-acetylbenzenesulfon with phosgene to yield a disulfonylurea, which is py amide thus prepared was collected by filtration. Recrys rolyzed in the presence of cyclohexyl or cycloheptyl tallization of the filter cake from aqueous ethanol yielded amine. All of these reactions yield the desired N-p- purified p-acetylbenzenesulfonamide melting at about acetylphenylsulfonyl- N'-cyclo-alkylurea. Compounds 176-179 C. represented by the above formula in which X is a sec EXAMPLE 2 ondary alcohol group, can also be prepared by reducing Preparation of N-p-acetylphenylsulfonyl the p-acetyl group of the sulfonamide, disulfonylurea or N'-cyclohexylurea sulfonylcarbamate to an a-hydroxyethyl group and, if 70 A reaction mixture consisting of 32.7 g. of p-acetyl necessary, protecting the hydroxyl group during subse benzenesulfonamide and 64 g. of anhydrous potassium quent reactions of the type outlined above utilized for carbonate in 350 ml. of anhydrous acetone was stirred 3,320,312 3. 4. at refluxing temperature for about one and one-half hours, in the above reaction was dissolved in ethanol, 50 ml. of thus forming the potassium salt of p-acetylbenzenesul water were added, and the solution was made acid to fonamide. 30.9 g, of cyclohexylisocyanate were added litmus by the addition of 12 N hydrochloric acid. Chill dropwise to the reaction mixture. Refluxing and stirring ing of the solution yielded crystals of N-p-acetylphenyl were continued during the course of the addition and for sulfonyl-N'-cycloheptylurea. The crystals were separated an additional 16 hours. The acetone was removed by by filtration, and after two-fold recrystallization from evaporation in vacuo, and about 750 ml. of water were aqueous acetone, melted at about 156-157 C. added to dissolve the resulting residue. The solution was EXAMPLE 6 filtered. The potassium salt of N-p-acetylphenylsulfonyl Preparation of N-p-(a-hydroxyethyl)phenyl N'-cyclohexylurea formed in the above reaction, being O sulfonyl-N'-cyclohexylurea Water soluble, passed into the filtrate. Acidification of the filtrate with 6 N aqueous hydrochloric acid caused 1 g. of N-p-acetylphenylsulfonyl-N'-cyclohexylurea was the precipitation of N-p-acetylphenylsulfonyl-N'-cyclo dissolved in 100 ml. of ethanol to which 10 ml. of water hexylurea which was collected by filtration. Recrystalliza had been added. About 1. g. of 5 percent palladium-on tion of the filter cake from 90 percent aqueous ethanol carbon catalyst was added, and the urea was hydrogenated yielded purified N-p-acetylphenylsulfonyl-N'-cyclohexyl under a hydrogen pressure of about 45 p.s. i. After the theoretical quantity of hydrogen had been absorbed, the urea melting at about 188-190° C. hydrogenation mixture was filtered to remove the cata EXAMPLE 3 lyst, and the filtrate was evaporated to dryness in vacuo. Preparation of ethyl N-(p-acetylphenyi 20 The residue comprising N-p-(a-hydroxyethyl)phenylsul sulfonyl)carbamate fonyl-N'-cyclohexylurea formed in the above hydrogena tion melted at about 150-152 C. after two-fold recrystal 65 g. of ethyl chloroformate were added dropwise with lization from aqueous ethanol. stirring to a reaction mixture containing 89 g. of p-acetyl For hydrogenations using larger amounts of N-p-acetyl benzenesulfonamide and 162 g. of anhydrous potassium 25 phenylsulfonyl-N'-cyclohexylurea, a mixture of ethanol carbonate in 550 ml. of anhydrous acetone. After the ad and dioxane can be employed in place of the aqueous dition had been completed, the reaction mixture was ethanol used in the above example. heated at refluxing temperature for about 18 hours, after N - p - (a-hydroxyethyl)phenylsulfonyl-N'-cycloheptyl which time it was cooled and was filtered. The filter urea can be prepared by hydrogenating N-p-acetylphenyl cake containing the potassium salt of ethyl N-(p-acetyl 30 sulfonyl-N'-cycloheptylurea with a palladium-on-carbon phenylsulfonyl)carbanate formed in the above reaction catalyst by the procedure set forth above. was dissolved in about 1.41. of water. The resulting solu tion was filtered to remove insoluble impurities, and was EXAMPLE 7 acidified to a pH of about 2 with 12 N hydrochloric acid, Preparation of the sodium salt of N-p-acetyl thus precipitating ethyl N-(p-acetylphenylsulfonyl)car phenylsulfonyl-N'-cyclohexylurea bamate which was then collected by filtration. Recrystal 1 g of N-p-acetylphenylsulfonyl-N'-cyclohexylurea was lization of the filter cake from an ethanol-water mixture suspended in 20 ml.
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