Unusually Facile Syntheses of Diquat (6,7-Dihydrodipyrido[1,2-<i>a</i>:2′,1′-<i>c</i>]pyrazinediium) and Related Cations

Abstract

A new and versatile method for the synthesis of cyclic diquaternary cations under mild conditions is described. Treatment of various α-diimines with 1,2-bis(triflyloxy)ethane in diethyl ether, chloroform, or dichloromethane at room temperature affords diquats in yields of up to 98%. © Georg Thieme Verlag Stuttgart.