Synthesis and Electrochemistry of Pyrimidoquinazoline-5,10-diones. Design of Hydrolytically Stable High Potential Quinones and New Reductive Alkylation Systems

Article abstract of DOI:10.1021/jo00253a010

The synthesis of pyrimido<4,5-g>quinazoline-5,10-diones 1 and pyrimido<5,4-g>quinazoline-5,10-diones 2 was carried out in conjunction with the design of both hydrolytically stable high potential quinones and new purine-like reductive alkylators.These systems consist of a benzoquinone ring bearing two fused pyrimidin-4(3H)-one rings.The fused pyrimidinone rings serve to protect 1 and 2 from hydrolysis as well as to raise quinone redox potentials by stabilizing the hydroquinones with internal hydrogen bonds (65 mV increase per hydrogen bond).Synthesis of 1 and 2 involved pyrimidinone ring annelation to a 2,5-diamino-3-nitroterephthalic acid derivative and to a 2,4-diamino-1,5-dicarboxy-3-nitrobenzene derivative, respectively.The synthetic studies provided insights into the electronic effects of nitro and amino groups on the annelation process.