Fluorine-containing heterocycles: Part III. Synthesis of some new furo[2,3-b]-, pyrazolo[3,4-b]- and thieno[2,3-b]pyridines with anticipated biological activities

Etify A. Bakhite, Abdu E. Abdel-Rahman, Elham A. Al-Taifi
2014 Arabian Journal of Chemistry  
Fluorine-containing heterocycles: Part III. Synthesis of some new furo[2,3-b]-, pyrazolo [3,4-b]-and thieno[2,3-b]pyridines with anticipated biological activities Abstract 3-Cyano-6-(2-thienyl)-4-trifluoromethylpyridine-2(1H)-one (1) and its thiono analog 2 were prepared by the reaction of (2-thenoyl)-x,x,x-trifluoroacetone with cyanoacetamide or cyanothioacetamide, respectively. Interaction of compound 1 with ethyl chloroacetate or chloroacetamide led to the regioselective formation of
more » ... ted pyridines 3 and 10. The latter compounds underwent some successive reactions to furnish the promising furopyridines (4 and 7-9) and pyrazolopyridines (12-15). The reaction of 2 with chloroacetamides or chloroacetonitrile furnished 2-functionalized 3-amino-6-(2-thienyl)-4-trifluoromethyl-thieno[2,3-b]pyridines (16a, b) which were used as key intermediates in the synthesis of the title thienopyridines. Structures of the newly synthesized compounds were established on the basis of their elemental and spectral (IR, 1 H NMR and mass) analyses.
doi:10.1016/j.arabjc.2014.05.035 fatcat:aepsx4kfgzbvzortri62qga2ke