Highly fluorescent 1,2-dihydropyrimido[1,6-alpha]indole: an efficient metal free synthesis and photophysical study

A metal free route to highly fluorescent 1,2-dihydropyrimido[1,6-alpha]indole derivatives has been developed via base catalyzed aldol followed by the Mannich reaction of indole-2-carboxaldehyde with ethyl N-arylideneglycinate at room temperature. This transformation consists of the sequential formation of two new bonds to afford highly functionalized pyrimidoindole derivatives under mild reaction conditions. Photophysical properties of the products have also been reported.