A chromeno[4,3-d]pyrazolo[3,4-b]pyridinone derivative 3 bearing thieno[2,3-d]pyrimidine moiety, 5-methyl-1-phenyl-3-(thieno[2,3-d]pyrimidin-4-yl)chromeno[4,3-d]pyrazolo[3,4-b]pyridin-6(3H)-one, was efficiently prepared in 75% yield by the reaction of 3-phenyl-1-(thieno[2,3-d]pyrimidin-4-yl)-1H-pyrazol-5-amine 1 with 3-acetyl-2H-chromen-2-one 2 presence FeCl3-SiO2 as a catalyst refluxing ethanol...

Pills of Mefenamic acid were  employed as effective catalysts in the three component reaction of aromatic  aldehydes,  malononitrile,  as  well  as  4-hydroxycoumarin  or  barbituric  acid  in  aqueous solution,  using  reflux  conditions  in  order  to  synthesize  derivatives  of  dihydropyrano[2,3-c]chromene and pyrano[2,3-d]pyrimidine, correspondingly. Among the benefits of this technique, ...

A series of naphthopyran derivatives 3a-f were prepared. Reaction of 2-amino-4-(p-chlorophenyl)-7-methoxy-4H-naphtho[2,1-b]pyran-3-carbonitrile (3b) with Ac2O afforded two products, 2-acetylamino-7-methoxy-4-(p-chlorophenyl)-4H-naphtho-[2,1-b]pyran-3-carbonitrile (4) and 10,11-dihydro-3-methoxy-9-methyl-12-(p-chloro-phenyl)-12H-naphtho[2,1-b]pyran[2,3-d]pyrimidine-11-one (5) and treatment of 3b...

4-Imino-1-p-tolyl-1,4-dihydropyrazolo[3,4-d]pyrimidin-5-ylamine (2) and (1-p-tolyl-1H-pyrazolo[3,4-d]pyrimidin-4-yl)-hydrazine (3) were prepared starting from ethyl 4-cyano-1-p-tolyl-1H-pyrazol-5-ylimidoformate (1). The structure of compound 3 was confirmed through preparation of the pyrazole derivatives 4 and 5. Also, the synthesis and structural characterization of pyrazolo[4,3-e][1,2,4]triaz...