1,3,9,11,12,14-Hexa-azapentacene-2,4,8,10(3H,9H,12H,14H)-tetraones (doubled 5-deazaflavins) with potential for oxido reduction

Abstract

Condensation of 8-(substituted-amino)1,5-dihydro-5-deazaflavins (3) with 6-chloro-5-formyluracils (4) gave the 1,5-dihydro doubled 5-deazaflavins (5) and 8-(5-formyluracil-6-yl)amino-1,5-dihydro-5-deazaflavins (6). The dehydrogenation of compounds (5) with diethyl azodicarboxylate or the dehydrative cyclization of compounds (6) with Vilsmeier reagent gave the corresponding 1,3,9,11,12,14-hexa-azapentacene-2,4,8,10(3H,9H,12H,14H)-tetraones(doubled 5-deazaflavins)(8). The latter exhibited strong autorecycling oxidation toward cyclopentanol giving, in sunlight under an oxygen atmosphere, cyclopentanone.