Doxazosin is a quinazoline derivative substituted with an amino group at position 4, methoxy groups at positions 6 and 7, and a piperazin-1-yl group at position 2, which is further substituted by a 2,3-dihydro-1,4-benzodioxin-2-ylcarbonyl group at position 4. It is an antihypertensive agent used in the treatment of high blood pressure. It functions as an alpha-adrenergic antagonist, vasodilator, antihyperplasia drug, and has antineoplastic properties. It belongs to the classes of quinazolines, N-acylpiperazines, N-arylpiperazines, benzodioxines, monocarboxylic acid amides, and aromatic amines.
