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A facile and green protocol for the synthesis of acridinedione derivatives (III) (19 examples) via Fe-catalyzed condensation of dimedone with aldehydes and NH4OAc is developed.

The title compounds are synthesized in an one-pot, four component reaction of phthaloyl dichloride (I) , hydrazine hydrate, various aryl aldehydes (II) and malononitrile (III), ethyl cynoacetate (V) or dimedone (VII) in refluxing water.

Products (IV) are also obtained by a two step procedure consisting of the reaction between (II) and (III) and then further transformation of the isolated product to (IV).

based on acid-catalyzed condensation reactions of chalcone derivatives (I) with phenylhydrazine and acetoacetanilide (V), respectively

Reaction of phthalic anhydride 1 with benzylidineanilines 2, in equimolar ratio in hot acetic acid, yields N-arylphthalimides 3. Compound 1 reacts with the arylimine part of the Schiff base eliminating benzaldehyde part 4 as the bye-product. This reaction of 1 with 2 is also found to occur with other anhydrides like succinic anhydride 5, maleic anhydride 7 and acetic anhydride 9 resulting in the formation of the corresponding N-arylimides, namely, succinicimide 6, maleicimide 8 and aceticimide 10 respectively. In all the above reactions, the by-product, i.e. benzaldehyde or p-chlorobenzaldehyde can be isolated and characterized as its 2,4-dinitrophenylhydrazone derivative. Probable mechanism for the formation of imides from the corresponding anhydrides and Schiff bases has been suggested.

The title compounds are prepared by the sol—gel method starting with Ln2O3 dissolved in HNO3, aqueous solutions of ZrO(NO3)2, and H2O2 solutions containing Ti powder and NH3 followed by heating of the obtained precursors (500—900 °C, 5 h).

Allenes bearing tethered nucleophiles undergo acylation-cyclization on treatment with acylcobalt complexes and base.

Derivatives of 2,4-diiodophenol are shown to undergo palladium catalyzed carbonylation and alkyne coupling reactions in excellent to moderate yield and high regioselectivity. The scope of these reactions is explored. Palladium catalyzed reactions are employed as the key steps in the synthesis of three phenolic natural products: Plicatin B, Drupanin and Eutypine.

Oxidative decarboxylation of azlactones by cerium(IV) ammonium nitrate yields 2-arylglyoxylamide in very good yields.