An Efficient Solid-Phase Synthesis of Quinazoline Derivatives

Significance

An efficient approach for the solid-phase synthesis of 2,3-disubstituted 8-arylamino-3H-imidazo[4,5-g]quinazolines 7 has been developed. Thus, reductive amination of resin 1 with arylamines 2 in the presence of NaBH₃CN gave the resin-bound arylamines 3. The reaction of 3 with 4-chloro-7-fluoro-6-nitroquinazoline, followed by the reaction with alkylamines afforded 7-alkyl­amino-4-arylaminoquinazolines 5 via intermediate 4. The reduction of the nitro group in 5 with SnCl₂×2H₂O and subsequent cyclization reaction with aldehydes were accomplished in one pot to afford imidazoquinazolines 6. The polymer support was cleaved with TFA to provide the desired quinazolines 7 in 12-95% yield.