Patent GB-940696-A (GB)
Title: 1, 2-diaryl-3, 5-dioxo-pyrazolidines and processes for their preparation
IPC: C07D405/06
Filed: 1961-02-23
Abstract: The invention comprises compounds of general formula <FORM:0940696/C2/1> (wherein R1 represents an alkyl radical (1-3C) and R2 represents hydrogen, an alkyl or alkoxy radical (1-4C), an alkyl-sulphonyl radical (1-3C), a halogen atom or a hydroxyl group, and R3 represents hydrogen or a hydrocarbon radical (1-10C) a chain of which can be interrupted by S, SO or SO2, or a ring of which can be interrupted by O, or a benzene ring of which can be substituted by a halogen atom); their tautomers; their salts with inorganic or organic bases; and their preparation by (1) condensing in the presence of an alkaline condensing agent a compound of formula <FORM:0940696/C2/2> (wherein R31 corresponds to R3 excepting interruption by SO or SO2 and X represents a hydrocarbon radical (1-8C)) with a compound of formula <FORM:0940696/C2/3> (wherein R21 corresponds to R2 excepting hydroxyl or is an aralkoxy radical or an a -alkoxy (1-4C)-alkyl (1-4C) radical in which the alkyl and alkoxy portions may join in a ring, and one of Y and Y1 is hydrogen and the other hydrogen or an aryl radical which is easily split off), or (2) by reacting in the presence of an acid binding agent a compound of formula <FORM:0940696/C2/4> (wherein Z represents chlorine, bromine or an acetoxy radical) with a compound of formula <FORM:0940696/C2/5> (wherein R211 corresponds to R21 or may be an acyloxy radical), or (3) reacting in the presence of an acid binding agent a compound of formula <FORM:0940696/C2/6> with a compound of formula <FORM:0940696/C2/7> and treating the reaction product with an alkaline condensing agent, and (4) treating the products of (1)-(3) not bearing a substituent R2 by hydrolysis or hydrogenolysis to form such compounds, if desired previously or subsequently oxidising a compound bearing a substituent R31 interrupted by S to one bearing a substituent R3 interrupted by SO or SO2, or (5) reacting in the presence of an N,N1-disubstituted carbodiimide a compound of formula <FORM:0940696/C2/8> with a compound of formula <FORM:0940696/C2/9> and hydrolysing or hydrogenolysing to form compounds bearing a substituent R2 as appropriate, or (6) oxidising a compound of formula <FORM:0940696/C2/100> wherein R2111 represents an alkylmercapto radical (1-3C) or corresponds to R2, or (7) condensing a product of (1)-(6) of formula <FORM:0940696/C2/111> with a compound of formula R311=O wherein R311 represents a geminal divalent hydrocarbon radical (1-10C) any ring of which can be interrupted by O or a benzene ring of which may be substituted by a halogen atom, and reducing the reaction product of formula <FORM:0940696/C2/122> and hydrolysing or hydrogenolysing to form compounds bearing a substituent R2 as appropriate.  The description refers to avoiding the use of an acid binding agent in process (2) above by using N,N1-dimetal derivatives of the hydrazobenzene starting materials.  Phenylthioethylmalonic acid dichloride is obtained from the acid with thionyl chloride. Pharmaceutical compositions:-The compounds and salts of the invention may be administered orally (e.g. as powders, tablets or capsules), rectally (e.g. as suppositories), or parenterally (as aqueous solutions of salts).  They have antiphlogistic, analgesic and uricosuric activity.