We report a Cu(I)-catalyzed synthesis of quinazolines via cascade cyclization/hydrodehalogenation by using acetamide as a nitrogen source and H₂O as a hydrogen source. The current reaction provides a unified modular route from readily available starting materials to quinazolines in which aryl aldehydes can be decorated with diverse substitutions. In this reaction, acetamide becomes an interesting alternative for the unpleasant smelling ammonia and toxic amidines.