Synthesis, Antifungal, and Antioxidant Evaluation of New Class of Thiazoloquinazoline Linked by Carbonyl with Nitrile, Phenylacrylonitrile, Pyrazole, Pyrazolo[1,5-a]pyrimidine and Triazolo[1,5-a]pyrimidine as Five and Six-Membered Heterocycles Derivatives

A specific route for the synthesis of a novel benzo[4,5]thiazolo[2,3-b]quinazoline (IVa–e), (VIa–e), (VIIa–e), (VIIIa–e), (IXa–e), and (Xa–e) derivatives, where established using thiazolo[2,3-b]quinazoline-3,6(5H,7H)-dione derivatives (Ia–e) as an efficient starting materials. The present report briefly outlines relevant synthetic methods employed for this class of new compounds and intensively reveals significant antifungal and antioxidant activities along with SAR studies. The results of this study indicate that the target compounds (VIIa–e) and (VIIIa–e) exhibited better antifungal activity at 100 μg/ml compared with standard Trifloxystrobin and Azoxystrobin, respectively while compounds (IXa–f) particularly compound (IXd) showed good antioxidant activity at 10 μg/mL. Structures of newly synthesized compounds were confirmed by elemental analysis and spectral IR, 1H NMR and 13C NMR.