Expedient synthesis of 1,2,4-triazinyl substituted benzo[<i>c</i>]coumarins via double oxidation strategy

Herein, we report a convenient one-pot synthesis of 1,2,4-triazinyl derivatives benzocoumarins. The proposed approach consists in the nucleophilic addition tetrahydrobenzo annulated dimethoxycoumarin to 1,2,4-triazines followed by double oxidation both dihydrotriazine and groups with 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ). was carried out presence three-fold excess methanesulfonic acid DCM at room temperature take place between positions 4 5 coumarin 1,2,4-triazine, respectively. step achieved 3.6 equivalent DDQ. Selective moiety, without affecting fragment, using 1.2 tetrachlorobenzoquinone (TCQ). differences TCQ DDQ appear be related higher oxidative potential contrast TCQ. advantages method are elimination use transition metals, availability starting materials, simplicity procedure. provides two-step protocol for triazinyl benzocoumarins, precursors preparation push-pull pyridinyl chromophore.