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Abstract Ethoxymethylene malononitrile and 4-hydrazino-7,9- dimethylpyrido[3’,2’:4,5]thieno[3,2-d]pyrimidine (1) was refluxed in absolute ethanol to give 5-amino-1-(7,9-dimethylpyrido[3’,2’:4,5]thieno[3,2-d]pyrimidin-4-yl)-1H-pyrazole-4- carbonitrile (2) in 58% yield. Nitrile derivative 2 was refluxed in 80% formic acid and/or acetic acid to afford 1-(7,9-dimethylpyrido[3’,2’:4,5] thieno[3,2-d]pyrimidin-4- yl)-1,5-dihydro-4H-pyrazolo[3,4-d]pyrimidin-4-one (3) and 1-(7,9- dimethylpyrido[3’,2’:4,5]thieno[3,2-d]pyrimidin-4-yl)-6-methyl-1,5- dihydro-4H-pyrazolo[3,4-d]pyrimidin-4-one (4), respectively A mixture of ethoxymethylene cyanoactate and 1 was refluxed in absolute ethanol to give 2-(7,9-dimethylpyrido [3’,2’:4,5]thieno[3,2-d]pyrimidin-4-yl)-3-oxo-2,3-dihydro-1H-pyrazole-4-carbonitrile (5) in 72% yield Acid hydrolysis was occurred for 5 which was refluxed in sulfuric acid 10% to give 2-(7,9-dimethylpyrido [3’,2’:4,5]thieno[3,2-d]pyrimidin-4-yl)-3-oxo-2,3-dihydro-1H-pyrazole-4-carboxylic acid (6) in 41% yield. Ethoxymethylene dimalonate and 1 was refluxed in absolute ethanol to give a powder of ethyl 2-(dimethylpyrido[3’,2’:4,5]thieno[3,2-d]pyrimidin-4-yl)-3-oxo-2,3-dihydro- 1H-pyrazole-4-carboxylate (7) in 95% yield. Hydrazinolysis of 7 gave a powder of 2-(7,9- dimethylpyrido[3’,2’:4,5]thieno[3,2-d]pyrimidin-4-yl)-3-oxo-2,3-dihydro- 1H-pyrazole-4-carbohydrazide (8) in 53% yield . Treatment of 1 with phenyl isothiocyanate afforded a solid product of 2-(7,9-Dimethylpyrido[3’,2’:4,5]thieno[3,2-d]pyrimidin-4-yl)-Nphenylhydrazinecarbothioamide (9) in 58% yield . A mixture of anhydrous sodium acetate in absolute ethanol was prepared to receive 9 and finally phenacyl bromide and/or ethylbromoacetate was added to get on a solid product of (2E)-3,4- diphenyl-1,3-thiazol-2(3H)-one (7,9-dimethylpyrido[3 ,2 :4,5]thieno[3,2-d]pyrimidin-4-yl)hydrazone (10) and (2E)-3- phenyl-1,3-thiazolidine-2,4-dione 2-[(7,9-dimethylpyrido [3’,2’:4,5]thieno[3,2-d]pyrimidin-4-yl)hydrazone] (11) in 71% yield. A mixture of acetylacetone and/or ethyleacetoacetate and 1 was refluxed in absolute ethanol to give 4-(3,5-dimethyl-1H-pyrazol-1-yl)- 7,9-dimethylpyrido[3’,2’:4,5]thieno [3,2-d]pyrimidine (12) in 78% yield and 2-(7,9-dimethylpyrido[3’,2’:4,5]thieno[3,2-d]pyrimidin-4-yl)-5- methyl-2,4-dihydro-3H-pyrazol-3-one (13) in 84% yield. (5Z)-5-Benzylidene-3-[(7,9-dimethylpyrido[3’,2’:4,5]thieno[3,2- d]pyrimidin-4-yl)amino]-3,5-dihydro-2-phenyl-4H-imidazol-4-one (15) was prepared in 75% yield by refluxing of the hydrazine derivative 1 and (4Z)-4-benzylidene-2-phenyl-1,3-oxazol-5(4H)-one (14) in dioxane and in the presence of a catalytic amount of acetic acid |