A Diversity Oriented Synthesis of 2,10-Dioxo-10H-1,2,3,4,4a,5-hexahydropyridazino[3,2-b]quinazolines

Abstract

A parallel method for the synthesis of the title compounds is described. Thus, methyl anthranilates (5) are transformed into 2-aminobenzohydrazides (3) which were treated with 4-oxo acids (4) to afford in high yields and acceptable purity of piridazino[3,2-b]quinazolines (1). Compounds (1) present four diversity centers (R 1 , R 2 , R 3 , and R 4 ). The range of chemically acceptable substituents at each center has been evaluated. The isolation of a possible intermediate in the formation of 1, which presents an aminol structure (10), has allowed proposing a complete mechanistic rationalization for the formation of structures (1).