Heterocyclisation of 2,5-diacetyl-3,4-Disubstituted-thieno[2,3-b]thiophene bis-Thiosemicarbazones leading to bis-Thiazoles and bis-1,3,4-Thiadiazoles as anti-Reast cancer agents

Abstract

In this paper, the synthesis of bis-thiazoles and bis-1,3,4-thiadiazoles linked to a thienothiophene nucleus is described. The synthesis was achieved through interaction between 2,5-diacetylthieno[2,3-b]thiophene bis-thiosemicarbazones with a variety of hydrazonyl halides in a basic medium. All the synthesised compounds were characterised by IR, 1H NMR, 13C NMR and mass spectroscopic analyses. The newly synthesised compounds represent a variety of novel polyheteroatomic moieties containing nitrogen and sulfur. Most of the synthesised compounds were evaluated for their antitumour activity against the breast cancer MCF-7 cell line. The results revealed that four compounds are equipotent to tamoxifen (IC50 = 8.04 μg mL-1) with IC50 = 8.23, 8.26, 8.68 and 9.12 μg mL-1 respectively.