Quinazoline derivatives exhibit a broad range of biological activities, finding use as anticancer, antimicrobial, antimalarial, and antiviral agents. Numerous 2-amino-6,7-dimethoxyquinazoline analogs are extensively employed as α1-adrenoreceptor blockers and in recent years quinazoline-based OLED materials have also gained attention. Several methods of selective C4 position modification are known, but the modification of the C2 position is still challenging. In this research, we employ the sulfonyl group dance to achieve 4-azido-2-sulfonylquinazolines, which inverse the regioselectivity and further undergo C2 substitution, yielding 2-amino-4-azidoquinazolines. The regioselectivity of the transformation was proven by chemical synthesis, NMR, and X-ray crystallography. Furthermore, we show the applications for these products in the synthesis of phosphoronylidenes, fluorescent 4-triazolylquinazolines, and the development of a novel synthesis pathway toward α1-adrenoreceptor blockers terazosin and prazosin.