Synthesis of bis chalcones and transformation into bis heterocyclic compounds with expected antimicrobial activity

Abstract

One-pot synthesis of novel derivatives of bis-chalcones has been achieved by condensation of 1,4-diacetylbenzene with different aldehydes in basic media. The reaction of chalcone derivatives 3a,b with thioglycolic acid gives compounds 4a,b. This, when reacted with ethyl cyanoacetate in presence of ammonium acetate gives the corresponding cyanopyridine derivatives 5a,b. Furthermore, bis-chalcone 3a,b has been cyclized to pyrazole analogs by using 2,4-dinitrophenylhydrazine to give compounds 7a,b in good yields. All products have been characterized by IR, ¹H and ¹³C NMR, and elemental analysis. The newly synthesised compounds have been screened for anti-bacterial activity.