Urea-based DES as an amine source to access nitrogen-containing heterocycles

[Display omitted] •Urea-based DES acts as an amine source, catalyst and solvent for the synthesis of styryl quinazolinones.•Changing the hydrogen bond acceptor in DES to provide different N-substituted styryl quinazolinones.•Overall reaction performed in the greener pathway.•Synthesized molecule acts as a security ink in an acidic medium. Herein, we report a urea-based DES that acts as an amine source in the synthesis of N-substituted styryl quinazolinone from anthranilic acid via N-acylation, cyclization, and subsequent sp3 CH functionalization under a green reaction medium. The salient features of this approach are gram-scale synthesis, mild reaction conditions, and a metal-free methodology. Additionally, post-functionalization and photophysical properties were evaluated.