Method for preparing 2-quinoxalinol

The invention discloses a method for preparing 2-quinoxalinol, which comprises the following steps: preparing 2-quinoxalinol-4-oxide by the cyclization of chloro-m-nitroacetoacetanilide serving as a raw material in the presence of a hydroxide; and preparing 2-quinoxalinol by reducing the 2-quinoxalinol-4-oxide with phosphorous acid or trimethyl phosphate serving as a reducer. In the invention, the phosphorous acid or trimethyl phosphate is used as a reducer to reduce 2-quinoxalinol-4-oxide with high selectivity to prepare 2-quinoxalinol, so the byproducts are reduced, and product yield and purity are high; the conditions of the reduction reaction are mild, and the possibility of explosion generated by low-pressure catalytic hydrogenation with hydrogen serving as a reducer is lowered; because the phosphorous acid or trimethyl phosphate commodity serving as the reducer is cheap and readily available, the production cost of the 2-quinoxalinol is reduced; and as the reaction raw materialsand the products produced