A FACILE SYNTHESIS OF ISOXAZOLO [5′,4′:4,5]THIAZOLO[3,2-a]THIENO PYRIMIDINES A NEW RING SYSTEM

On the chemistry of 5‐aryl‐2‐hydrazino‐benzo[6,7]cyclohepta[1,2‐b]pyrido[2,3‐e] pyrimidin‐4‐one

“…The cyclization of 2-hydrazino derivatives with formic acid and/or carbon disulfide at N-3 nitrogen atom producing the 1,2,4-triazolo pyrimidinone was previously noted [11,12]. Also, the 2-hydrazino derivative 1 was used for the preparation of pyridopyrimidotriazine derivative 5.…”

Crystal and Molecular Structure of 7‐Methyl‐5,6,7,8‐tetrahydro[1]benzothieno[2,3‐d]pyrimidin‐4[3H]one

“…Also, some are clinically effective antiallergic 11 , potentially antineoplastic agents 12 , or have significant hypocholesterolemic activity 13. These aspects prompted us to prepare new polyheterocyclic fused systems containing the thienopyrimidine moiety with potential biological activity during our search for new compounds of pharmacological interest [14][15][16] .…”

Synthesis of Polynuclear Heterocyclic Compounds Derived from Thieno[2,3-d]pyrimidine Derivatives

“…The biological [1][2][3][4][5], bactericidal [6], and medicinal [7,8] activities of thieno [2,3-d]-pyrimidine derivatives have stimulated considerable research in this field [9][10][11][12]. In continuation of our work on the synthesis of fused pyrimidine derivatives [13], we report here the utility of 3-methyl-2-methylthio-3,4-dihydrotheino [2,3-d]pyrimidine-4-one derivatives 1a,b for the synthesis of azolothienopyrimid-ines, thienopyrimido-as-triazines, pyrazolylthienopyrimidines and tetrazolothienopyrimidines.…”