1-1-diphenyl-2-picrylhydrazyl and thienopyrimidine

This study represents the synthesis of a new series of N-substituted phenyl-5-methyl-6-(5-(4-substituted phenyl)-1,3,4-oxadiazol-2-yl)thieno[2,3-d]pyrimidin-4-amine derivatives (4a-l) and substituted phenylamino-5-methylthieno[2,3-d]pyrimidine-6-carboxylic acid derivatives (3a-d). The newly synthesized compounds were characterized by (1)H NMR, (13)C NMR, LC-MS and IR analyses. All these novel compounds were screened for their in vitro antioxidant activity by employing DPPH, hydrogen peroxide, and nitric oxide radical scavenging assays. Compounds 4k, 4j, 4d, and 4e showed significant radical scavenging due to the presence of electron donating substituent on both sides of the thienopyrimidine ring enhances the activity and electron withdrawing groups like nitro decrease.

Topics: Antioxidants; Biphenyl Compounds; Free Radical Scavengers; Hydrogen Peroxide; Nitric Oxide; Oxadiazoles; Picrates; Pyrimidines

Dimethyl acetylenedicarboxylate, ethyl propiolate, and E-dibenzoylethylene react with thienopyrimidines (cyclo-pentyl, -hexyl, and -heptyl) derivatives to form thiazolo[3,2-a]thieno-[2,3-d]pyrimidin-2-ylidene) acetates, thieno[2,3-d]pyrimidin-2-ylthioacrylates, and thieno[2',3':4,5]pyrimido[2,1-b][1,3]thiazin-6-ones, respectively. Reactions proceed via cyclization and thio-addition processes. Some derivatives of thienopyrimidines showed high inhibition of Hep-G2 cell growth compared with the growth of untreated control cells. However, the fused heptyl of thienopyrimidothiazines indicates a promising specific antitumor agent against Hep-G2 cells with IC(50 )< 20 microM.

Topics: Antineoplastic Agents; Antioxidants; Biphenyl Compounds; Cell Proliferation; Cells, Cultured; Cyclization; Dose-Response Relationship, Drug; Drug Evaluation, Preclinical; Drug Screening Assays, Antitumor; HCT116 Cells; Hep G2 Cells; Humans; Picrates; Pyrimidines; Structure-Activity Relationship