A Facile Heterogeneous Catalytic Approach for One-Pot Synthesis of Fused Benzoxazinones Using Cuβ Zeolite and Evaluation of Biological Activities

A simple heterogeneous catalytic process has been established for the single-step synthesis of fused benzoxazinones, quinazolinones, and thiadazines through Markownikoff's hydroamination followed by intramolecular cyclization using Cuβ zeolite. The probability and limitations of this catalytic approach were explored using various substrates. The efficiency and feasibility of scaling up the current catalytic system were demonstrated through gram-scale experiments. Moreover, the catalyst was reused for up to five cycles with no noticeable decrease in its catalytic effectiveness. Furthermore, the synthesized compounds were subjected to in vitro assessment to determine their potential as anticancer agents against human cervical epithelioid carcinoma (HeLa), mouse breast cancer (4T-1), and human lung adenocarcinoma (A-549) cell lines. Cytotoxicity studies revealed that 3f, 3b′, 3d′, and 3g′ compounds exhibit anti-cancer activity against breast, cervical and lung cancer cells. Additionally, their antimicrobial activity against bacteria and yeast was also evaluated. The compound 3i exhibited superior antifungal activity against Candida albicans.