Classifications

• • C—CHEMISTRY; METALLURGY
  • C07—ORGANIC CHEMISTRY
  • C07D—HETEROCYCLIC COMPOUNDS
  • C07D401/00—Heterocyclic compounds containing two or more hetero rings, having nitrogen atoms as the only ring hetero atoms, at least one ring being a six-membered ring with only one nitrogen atom
  • C07D401/02—Heterocyclic compounds containing two or more hetero rings, having nitrogen atoms as the only ring hetero atoms, at least one ring being a six-membered ring with only one nitrogen atom containing two hetero rings
  • C07D401/04—Heterocyclic compounds containing two or more hetero rings, having nitrogen atoms as the only ring hetero atoms, at least one ring being a six-membered ring with only one nitrogen atom containing two hetero rings directly linked by a ring-member-to-ring-member bond

Definitions

• This invention relates generally to 4-pyridylpyridazinone derivatives which exhibit valuable antiinflammatory and analgesic activity in warm-blooded animals.
• the invention also relates to novel pharmaceutical compositions containing active 4-pyridylpyridazinone compounds and their use for inducing or obtaining antiphlogistic and/or analgesic effects in mammals.
• U.S. Patent No. 3,689,652 discloses 6-(substituted- phenyl)-4,5-dihydro-3(2H)-pyridazinones as hypotensive agents. More specifically, 6-halomethylphenyl-5-methyl (or unsubstituted)-4,5-dihydro-3(2H)- pyridazinone compounds are- disclosed. In related U.S. Patent Nos.
• the patentees further disclose corresponding 6-substituted phenyl-4,5-d ⁇ hydro-pyridazinone compounds wherein the additional phenyl substituents include lower alkanoyl, nitro, amino, lower alkanoylamino and cyano wherein the 2- position of the pyridazinone ring may be optionally substituted by lower alkyl.
• U.S. Patent No. 3,657,242 discloses a series of 4,5-dihydro-pyridazin- (2H)-3-one and hexahydropyridazines and, more specifically, certain 2-hydroxy- alkyl-6-aryl or heterocyclic substituted-4,5-dihydro-pyridazinones and hexa ⁇ hydropyridazines useful as antiinflammatories. • *
• the foregoing compounds are representative of 4,5-dihydro- pyridazinone compounds previously suggested as pharmacologically active compounds.
• the foregoing compounds comprise dihydro (saturated) ketopyridazines.
• pyridaz-3-one compounds disclosed in U.S. Patent No. 2,839,532.
• the aforesaid patent is directed to 4,5-u ⁇ saturated pyridaz-3-one (or 3-ketopyridazine) compounds having a cyano, acetyl, carboxyl, earbethoxy or benzoyl group in the 4- position optionally substituted in the 5,6- positions by lower alkyl, phenyl or substituted phenyl residues.
• These compounds are disclosed as being useful as medicaments, particularly, analgesics, anesthetics, antibacterials or disinfectants.
• analgesics, anesthetics, antibacterials or disinfectants u.S. Patent No. 3,491,096 and British Patent No.
• 840,522 are directed to other previously investigated pyridazone compounds.
• the aforementioned British patent pertains to 2-hydroxymethyl-6-phenyl-3-pyridazone and the analgesic utility thereof.
• U.S. Patent No. 3,491,096 describes 2-pyridylalkyla.ted- 6-phenyl-pyridaz-3-one compounds possessing sedative, analgesic and antispas- modic properties, with occasional hypo tensive effects being observed.
• novel 4-pyr ⁇ dylpyridazinone compounds which evidence effective antiinflam ⁇ matory and analgesic activity in warm-blooded animals.
• a method is provided for the treatment of inflammation, swelling, fever and the like conditions in mammals by the administration of preselected dosages of active 4-pyridyl- pyridaz ⁇ none compounds or pharmaceutically acceptable salts thereof in suitable nontoxic pharmaceutical dosage unit forms or compositions.
• novel, stable nontoxic pharmaceutical compositions and/or formulations adaptable for, e.g., oral, rectal, parenteral, etc., administration are provided.
• novel class of compounds of the present invention are various 4- pyr ⁇ dylpyridazinone compounds of the general formula I below:
• R is hydrogen, hydroxyalkyl or alkoxycarbonylalkyl
• R. is 2-pyridyl, 3- pyridyl or 4-pyridyl
• RRON and R are the same and represent phenyl, halophenyl or alkylphenyl.
• alkyl and alkoxy are inclusive of straight and branched chain carbon-carbon linkages, e.g., methyl, ethyl, N-propyl, isopropyl, N-butyl, tert- butyl, etc., and represent 1 to 5 carbon atoms.
• pharmaceutically acceptable nontoxic salts as used herein is intended to include those salts capable of being formed with the instant compounds and substituted derivatives thereof in accordance with the invention without materially altering the chemical structure or pharmacological properties of the parent compounds.
• acids for reaction with sufficiently basic pyridazinone derivatives include hydrochloric, hydrobromic, hydroiodic, nitric, phosphoric, citric, etc.
• Alkali metal salts of carboxylic acid derivatives of the invention may be obtained by reaction with suitable bases, e.g., sodium hydroxide, potassium hydroxide, etc. Alkaline earth metal salts may be similarly obtained.
• keto compounds of the above formula wherein R, is hydrogen may be present in the enol tautomeric form. It is also noted that the other possible R, substituents, i.e., hydroxyalkyl and alkoxycarbonylalkyl, constitute possible enol ⁇ e derivatives and/or metabolites of compounds within the scope of the present invention.
• the 4-pyridylpyr ⁇ daz ⁇ none i.e., substituted keto-pyridazine, compotmds of the present invention, may be prepared by various alternative methods heretofore employed in the synthesis of other pyridazinone compounds or modifications thereof to obtain the R., R,*, R restroom or , substituents thereon as defined above.
• one method for the preparation of the 4-pyridylpyr ⁇ - dazinone compounds of the present invention comprises reacting an -appropriately substituted monohydrazone, with pyridyl acetic acid ethyl ester or reacting the appropriately substituted benzil and pyridyl substituted hydrazide under cyclization conditions, e.g., in the presence of suitable solvents, such as xylene ⁇ acetonitrile, methanol, benzene, etc., and alkaline condensing agents, such as hydroxides, alcoholates, hydrides, alkali or alkaline earth metals, tertiary amines, etc., to effect ring closure.
• suitable solvents such as xylene ⁇ acetonitrile, methanol, benzene, etc.
• alkaline condensing agents such as hydroxides, alcoholates, hydrides, alkali or alkaline earth metals, tertiary amines
• the monohydrazone reactants may be prepared by the reaction of an appropriately substituted benzil with hydrazine hydrate.
• Suitable benzil starting materials may be obtained commercially or prepared by known methods, for example, cyanide ion catalyzed benzoin condensation followed by oxidation.
• the pyridazin(2H)-3-one compounds thus prepared may be utilized following recrystallization/pur ⁇ fication as an intermediate for the preparation of further 2-substituted derivatives in accordance with the above R, definition as illustrated more particularly in the specific examples of preferred embodiments of the invention hereinafter.
• the compounds of the present invention evidence antiinflammatory and analgesic effects in warm-blooded animals. It will be appreciated, however, that the specific response elicited upon administration of the compounds of the present invention to an animal species in need thereof will vary depending upon the specific structure of the administered compound, the unit dose, dosage regimen and mode of administration, as well as the particular mammalian species involved. Accordingly, as detailed hereinbelow, certain of the compounds of the invention are preferred over others relative to a predetermined pharmacological activity.
• Representative of preferred compounds of formula I for use in the analgesic compositions and methods of the present invention are 2-acetic acid-4- (4'-py ⁇ idyl)-5,6-diphenylpyridazin(2H)-3-one, ethyl ester; 4-(3 , -py ⁇ idyl)-5,6-bis(4 , - methylphenyl)pyridazin(2H)-3-one hydrochloride; 2-hydroxyethyl-4-(2 , -pyridyl)- 5,6-diphenylpyridazin(2H)-3-one hydrochloride; 4-(3 , -pyridyl)-5,6-diphenyl- pyridazin(2H)-3-one; and 4-(3'-pyridyl)-5,6-bis(4'-chlorophenyl)pyridazin(2H)-3- one.
• especially preferred compounds falling within the aforesaid general formula I are 2-acetic acid-4-(4 , -pyridyl)-5,6-diphenylpyridaz ⁇ n(2H)-3-one, ethyl ester; 2-hydroxyethyl- 4-(2 , -pyridyl)-5,6-diphenylpyridazin(2H)-3-one hydrochloride; and 4-(3 ⁇ -pyridyl)- 5,6-diphenylpyridazin(2H)-3-one.
• the active compounds of the invention may be administered alone or in combination with each other or administered in admixture with pharmaceutical diluents, carriers, excipients or adjuvants suitably selected with respect to the intended route of administration and conventional pharmaceutical practices.
• pharmaceutical diluents, carriers, excipients or adjuvants suitably selected with respect to the intended route of administration and conventional pharmaceutical practices.
• the active compound or compounds of the invention may be combined with such excipients as starch, lactose, sucrose, cellulose, magnesium stearate, and the like.
• injectable dosage unit forms may be utilized to accomplish intraveneous, intramuscular or subcutaneous administration and, for such parenteral adminis ⁇ tration, suitable sterile aqueous or nonaqueous solutions or suspensions, optionally containing appropriate solutes to effectuate isotonieity, will be employed.
• suitable sterile aqueous or nonaqueous solutions or suspensions optionally containing appropriate solutes to effectuate isotonieity.
• suitable adjuvants and dosage forms will be apparent to those skilled in the art.
• Compounds of the invention or compositions thereof may * be administered to warm-blooded animals, i.e., mammals, including, for instance, mice, rats, guinea pigs, dogs and other domesticated animals, or humans. .
• Dosages sufficient to elicit the above-identified antiinflammatory and/or analgesic response will generally range between about 1 to about 500 mg/kg/day in laboratory mice based upon body weight, and preferably between about 10 to about 200 mg/kg/day.
• the foregoing dosages will normally be administered in 3 or 4 divided doses, depending upon the desired dosage regimen.
• the actual effective dosage to be administered will vary, depending upon the specific compound involved, as well as the age, weight and responsiveness of the particular species.
• the compounds of the invention exhibit relatively low toxicities and the acute oral LD 50 (lethal dose to 50 percent of mice) will generally be greater than 300 mg/kg.
• Example 2 The compound of Example 2 (9.0 g.) and ethylene carbonate 2.7 g. 0 were slurried in DMF (100 mL.) and 3 powdered KOH pellets added. The reactants were stirred at 110-120° for 2 hrs. The mixture was poured into water and the suspension extracted with benzene. The organic layer was washed with water and dried over Na 2 SO ,. HC1 gas was bubbled through the solution to give a gummy precipitate which solidified on addition of ether. The solid was separated and recrystallized from MeOH-EtOAc. Yield 7.2 g., M.P. 237-247° C, decomposition with effervescence.
• Antiinflammatory activity i.e., effectiveness in the prevention and inhibition of granuloma tissue formation, is demonstrated by relative inhibition of carrageenin-induced edema as determined by the diminution of experimental edema induced in the hind paw of a rat by the injection of carrageenin.
• the procedure employed is a modification of the method of Winter et al, Proc. Soc. Exptl. Biol. Med., 111:544 (1962).
• the device used for measurement of the paw volume is an adaptation of the. water displacement procedure described by Adamkiewicz et al, Can. J. Biochem. Physiol., 33:332 (1955). Test compounds were administered orally, one hour prior to the intraplanter injection of 0.05 mL. of sterile 1.0% solution of carrageenin into the left hind paw of male rats (Long Evans strain) weighing between about 130-200 g. At peak swelling time (3 hrs.) the volume of edema was calculated by differential paw
• Table I sets forth results obtained at the indicated dosages with representative compounds of the present invention.
• Phenylquinone writhing test was employed to evaluate analgesic activity for selected compounds for the present invention according to the following procedure:
• Phenylquinone (phenyl-p-benzoqu ⁇ none, No. 7104, Eastman Organic Chemicals) is made up as a 0.02% aque ⁇ us solution and 5% ethyl alcohol. Phenylquinone solutions are made up fresh twice daily. Standard reference agents and the test compounds are dissolved or suspended in a 0.25% methyl- cellulose solution. ' A control group consisting of 10 mice (Carworth CF. male mice) are administered the 0.02% phenylquinone solution at a dose of 0.25 mL./mouse. The mice are housed individually and observed closely for 10 min. for exhibition of writhing. The onset of writhing occurs within 3 min.
• mice are administered orally to groups of 10 mice. The volume given is 0.01 mL. per gram of body weight. Activity can be studied at 15, 30, 60 and 120 min. after oral administration. After the designated time interval of a dose group has elapsed, the mice are challenged with phenylquinone intraperitoneally. "Complete blocking of the
• the compounds of the present invention were further tested to determined if they exhibited adverse neurotoxic effects.
• a standard testing procedure was employed to determine the mean neurotoxic dose in 50% of test mice.
• the mean neurotoxic dose (expressed as NTD 5Q value in mg/kg) is defined as that dose of the drug administered orally or intraperitoneally (i.p.) to test mice that causes minimal recognizable neurotoxicity in 50% of the animals tested.
• the procedure followed is described by Swinyard et al, J. Pharmac. Exp. Therap., 106, 319-330 (1952).

Landscapes

• Chemical & Material Sciences (AREA)
• Organic Chemistry (AREA)
• Pharmaceuticals Containing Other Organic And Inorganic Compounds (AREA)
• Plural Heterocyclic Compounds (AREA)

Applications Claiming Priority (2)

Publications (2)

Family

ID=23162890

Family Applications (1)

Country Status (5)

Families Citing this family (4)

Family Cites Families (9)

• 1982
  • 1982-08-18 JP JP57503139A patent/JPS58501432A/ja active Pending
  • 1982-08-18 EP EP19820903161 patent/EP0088128A4/de not_active Withdrawn
  • 1982-08-18 WO PCT/US1982/001118 patent/WO1983000863A1/en not_active Application Discontinuation
  • 1982-09-09 IT IT49095/82A patent/IT1149073B/it active
  • 1982-09-10 IL IL66761A patent/IL66761A0/xx unknown

Non-Patent Citations (2)

Also Published As

Similar Documents

Legal Events