A facile synthesis of substituted 3-amino-1<i>H</i>-quinazoline-2,4-diones

Abstract

A new synthesis of a series of 3-amino-1H-quinazoline-2,4-diones is described. The 1H-quinazoline-2,4-dione 10 was made starting with fluorobenzoic acid in three high yielding steps. The key step of this synthesis involved the generation of the dianion of urea 7 and the subsequent intramolecular nucleophilic displacement of the 2-fluoro to form the quinazolinedione ring. The 3-amino moiety was incorporated using (2,4-dinitro-phenyl)-hydroxylamine as the aminating reagent.