8 - Hydroxyquinoline Nitrification

The mononitration and dinitration of 8-Hydroxyquinoline were explored in the nitration system of HNO₃/H₂SO₄,KNO₃/H₂SO₄,Cu(NO₃)₂·3H₂O/acetic anhydride and KNO₃/AlCl₃.8-hydroxyquinoline take the dinitration as the primary reaction in the nitration system of HNO₃/H₂SO₄,KNO₃/H₂SO₄,and mononitration in the nitration system of Cu(NO₃)₂·3H₂O/acetic anhydride or KNO₃/AlCl₃.The effects of feeding order,ration and temperature on the main production and the selectivity were discussed here.In nitration systems of HNO₃/H₂SO₄ and KNO₃/H₂SO₄,compare to the mixed acid nitration system,the KNO₃/H₂SO₄ nitrification system has the advantages of higher nitration ability, lower by-product of oxidative reaction,higher speed of reaction and better selectivity of reaction.80.1%yield of the compounds of dinitration could be obtained under the optimal conditions with less than a yield of 1%of the mononitration.The nitration capabilities of Cu(NO₃)₂·3H₂O/acetic anhydride,KNO₃/AlCl₃ nitration system were moderate which can successfully complete the regional nitration of 8-hydroxyquinoline under certain conditions. Feeding order,ration and the reaction temperature have significantly impacts on the target product and the selectivity.The satisfactory yield and high selectivity of mononitration could be obtained under rigid controlling of the reaction temperature,feeding order and material ratio Under optimum conditions,the yields of mononitration are 93.9%and 73.3% respectively,both of the two selectivities are above 95%.The structure of the target product is characterized by ¹H-NMR,IR and MS.