Heterocyclic 1,3-diketones are important intermediate compounds in organic synthesis and find widespread use as extracting agents, analytical reagents, and as ligands in coordination chemistry [1,2]. In terms of our current scientific plan in searching for novel heterocyclic ligands there arose the need to prepare a series of dibenzoylmethane analogs which contain different pyrazole substituents.A few reports are in the literature on these compounds synthesis. Most of the publications relate to the preparation of acyl pyrazolone derivatives [3, 4] but reported methods cannot be used for the preparation of the target compounds. The reaction of 1,3,4,6-tetracarbonyl compounds with hydrazines to give 1,3-diketones has also been reported [5] but this method is not universal and requires hardly obtainable starting materials.The most obvious route to synthesis of the pyrazole-containing diketones is a Claisen condensation of the corresponding carbonyl compounds in the presence of a base. This method has been little studied because of the relatively poor availability of pyrazole ketones. Data existing in the literature is restricted, in all, to a few examples, viz. the condensation of 1-(1,3,5-trimethyl-1H-pyrazol-4-yl)ethanone with ethyl acetate in the presence of sodium ethylate [6] and the reaction of ethyl 1-alkylacetyl-4-methyl-1H-pyrazole-5-carboxylates, also with ethyl acetate [7].We have previously reported a general method for the synthesis of isomeric pyrazolyl ketones. This work now relates to the reaction of compounds 1 with the pyrazole carboxylates 2 and with certain other esters in the presence of bases.

A new catalytic system containing ferric chloride, activated carbon, and hydrazine has been proposed for the reductive cyclization of -dialkylamino-2-nitrostyrenes to give the corresponding indoles (Leimgruber-Batcho synthesis). Various substituted indoles may be obtained in high yield under these conditions.

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