SYNTHESIS AND REACTIONS OF SOME 3-CYANO-4-METHYLCOUMARINS

o-Hydroxy ketones (I) were converted into 3-cyano-4-methylcoumarins (I I) via condensation with ethyl cyanoacetate in presence of piperidine or ammonium acetate as a catalyst. The behavior of compound (II) towar ds Grignard and Michael reactions was investigated. The reactions of 3 -acetylcoumarin (III) with hydrazines under different conditions were carried out to give the hydrazone (IV a), phenylhydrazone (IV b) and p yrazole (V) derivatives. Also, the 4-styryl derivatives (VI) were obta ined by condensation of II with different aromatic and heterocyclic al dehydes. A one pot synthesis of Micheal product (VII) from the reactio n of VI with malononitrile was described.