ES453907A1 - Procedure for the preparation of pirazolone derivatives. (Machine-translation by Google Translate, not legally binding) - Google Patents

Abstract

Procedure for the preparation of pyrazolone derivatives of general formula I **(See formula)** where R1 signifies hydrogen, trifluoromethyl or an alkyl, aryl, aralkyl or heteroaryl moiety, where the above mentioned moieties may optionally be substituted and R2, in the event that R1 signifies hydrogen, trifluoromethyl, alkyl with more than 4 carbon atoms, substituted heteroaryl or aryl or aralkyl, means an unsubstituted naphthyl residue, and, otherwise, R2 means a substituted naphthyl residue, which can have 1 to 3 equal or different substituents of the halogen, trifluoromethyl, alkyl, alkenyl, alkoxy, alkylamino group., cyano, trifluoromethoxy, nitro, hydroxy, SOn-alkyl (n = 0 to 2) or SOn-trifluoromethyl (n = 0 to 2), where optionally two substituents on the aryl moiety together signify an isocyclic or heterocyclic ring, 5- to 7-membered, branched or unbranched, saturated or unsaturated, which may contain 1 to 2 oxygen or sulfur atoms, or a biphenyl moiety, characterized in that A) hydrazines of formula II R2-O-CH2-OH2-NH-NH2 (II) where R2 has the meaning indicated above, they are reacted with derivatives of the β-keto acid of formula III **(See formula)** where R1 has the meaning indicated above, and X means a protruding moiety, such as the hydroxy, alkoxy, aralkoxy, amino or alkylamino moiety, optionally in the presence of inert solvents and basic or acidic catalysts, such as alkali hydroxides and carbonates and alkaline earth, or such as hydrohalic acids, sulfuric acid or sulfonic acids, at temperatures between 10 and 200ºC, or B) Naphthoxyethyl derivatives of formula IV R2 - O - CH2 - CH2 - A (IV) where R2 has the meaning of above and A means a leaving moiety, such as halogen or the dialkyloxonium, dialkylsulfonium or trialkylammonium moiety or the aryl or trifluoromethyl sulphonic acid moiety, with pyrazolone derivatives (5) of formula V **(See formula)** where R1 has the meaning indicated above, optionally in the presence of inert solvents and inorganic or organic bases, such as alkali hydroxides, carbonates, alcoholates, hydrides or amides, at temperatures between 10 and 200ºC, or C) derivatives of acetylenecarboxylic acid of formula VI **(See formula)** where R1 has the meaning of above and Z2 means a hydroxy, alkoxy, aralkoxy, amino or alkylamino moiety, it is reacted with hydrazine of formula II R2 - O - CH2 - CH2 - NH - NH2 II where R2 has the meaning above, optionally in the presence of an inert solvent and inorganic or organic bases at temperatures between 50º and 200ºC. (Machine-translation by Google Translate, not legally binding)