Visible light-induced C–H alkylation of 1,2,4-triazine-3,5(2H,4H)-diones using hypervalent iodine reagents as alkylating sources

Abstract

A visible light-induced C–H alkylation reaction of 1,2,4-triazin-3,5(2H,4H)-diones has been achieved using iodo-methyltrimethylphthalate esters as alkylating agents with the advantages of metal or organic-catalyst-free nature, operational simplicity, mild conditions, broad substrate scope, and low sensitivity to environmental fluctuations. Notably, the strategy was successfully implemented in a microfluidic reactor with satisfactory yields. Among them, the drug precursor C₆-isopropylated-1,2,4-triazine-3,5(2H,4H)-dione was obtained in 70% yield via microfluidic synthesis, significantly shortening the synthetic route. This approach provides a green, efficient, and promising platform for synthesising bioactive C₆-alkylated 1,2,4-triazin-3,5(2H,4H)-dione derivatives.