Solid-Phase Synthesis of Fused [2,1-b]-Quinazolinone Alkaloids

Significance

Solid-phase synthesis of fused [2,1-b]quinazolinone alkaloids was developed. Thus, the reaction of PS-p-nitrophenyl carbonate 1 with anthranilic acids 13 gave carbamates 2. Condensation of 2 with lactams 14 using DCC and DMAP in CH₂Cl₂ afforded 3 and 4. During TFA-mediated cleavage of the benz­imides 3 and 4, the resulting aniline intermediates were cyclized under cleavage conditions to give deoxyvasicinone derivatives 7 and 6,7,8,9-tetrahydropyrido[2,1-b]quinozolin-11-ones 8 in good yield (87-90% yield from 1).