Study on the regioselectivity of the N-ethylation reaction of N-benzyl-4-oxo-1,4-dihydroquinoline-3-carboxamide

Beilstein J Org Chem. 2019 Feb 12:15:388-400. doi: 10.3762/bjoc.15.35. eCollection 2019.

Abstract

4-Oxoquinolines are a class of organic substances of great importance in medicinal chemistry, due to their biological and synthetic versatility. N-1-Alkylated-4-oxoquinoline derivatives have been associated with different pharmacological activities such as antibacterial and antiviral. The presence of a carboxamide unit connected to carbon C-3 of the 4-oxoquinoline core has been associated with various biological activities. Experimentally, the N-ethylation reaction of N-benzyl-4-oxo-1,4-dihydroquinoline-3-carboxamide occurs at the nitrogen of the oxoquinoline group, in a regiosselective way. In this work, we employed DFT methods to investigate the regiosselective ethylation reaction of N-benzyl-4-oxo-1,4-dihydroquinoline-3-carboxamide, evaluating its acid/base behavior and possible reaction paths.

Keywords: alkylation; carboxamide; oxoquinoline; quinolone; regioselectivity.