Reactions of 6-acetyl-4-methyl-5-(1-pyrrolyl)-2-phenylthieno-[2,3-d]pyrimidine in heterocyclic synthesis:: Convenient route to some Schiff's bases, chalcones, pyridines, pyridin-2(1H)-ones and 2H-pyran-2-one derivatives incorporating a 5-(I-pyrrolyl)-2-phenylthieno[2,3-d]pyrimidine moiety

Treatment of 6-acetyl-5-amino-4-methyl-2-phenylthieno[2,3-d]pyrimidine 3 with 2,5-dimethoxytetrahydrofuran afforded the 6-acetyl-5-(1-pyrrolyl)-4-methyl-2-phenylthieno[2,3-d]pyrimidine 4, which can react with appropriate primary amines 5a-f to yield the corresponding Schiff's base derivatives 6a-f. The reaction of acetyl compound 4 with appropriate arylaldehydes 14a-k and arylmethylidenemalononitriles 18a-afforded the corresponding 6-(3-substituted-acryloyl)-5-(1-pyrrolyl)-4-methyl-2-phenylthieno[2,3-d]pyrimidines 15a-k and 6-[3-cyano-2-ethoxy-4-(4-substituted-phenyl)-pyridin-6-yl]-5-(I-pyrrolyl)-4-methyl-2phenyl-thieno[2,3-d]pyrimidines 21a-f under basic conditions, respectively. On the other hand, the 6-(3cyano-1,2-dihydro-4-substituted-2-oxopyridin-6-yl)-5-(1-pyrrolyl)-4-methyl-2-phenylthieno[2,3-d]pyrimidines 26a,b and 6-(3-substituted-amido-4-substituted-pyran-2-on-6-yl)-5-(I-pyrrolyl)-4-methyl-2-phenylthieno[2,3-d]pyrimidines 30a-c were obtained by intramolecular cyclization of 6-(3-dimethylamino-3s ubstituted-acryloyl)-5-(1-pyrrolyl)-4-methyl -2-phenylthieno [2,3-d]pyrimidines 23a,b with cyanoacetamide 24 and N-acylglycines 27a,b, respectively.