Preparation
Synthesis of 8-aminoquinoline: Under an ice bath, sulfuric acid (2.0 mL) was added onto quinoline (5 mmol, 1.0 equiv) then 65% nitric acid (3.0 equiv) were added dropwise and stirred for 4h at rt. The mixture was poured into the ice water and neutralized with NaOH; and then extracted with dichloromethane. After dried over Na2SO4 and evaporated in vacuo, used next step without purification.
Mixture of nitroquinolines and 5% Pd/C was solved in ethanol and suspension was saturated with hydrogen gas under atmospheric pressure at 40°C until the starting material was consumed. 2 h later, the mixture was filtered and evaporated. The crude product was purified by silica gel column chromatography, eluting with EtOAc in hexanes to yield the desired 8-aminoquinoline is isolated as a brown solid in a yield of 32%.
Obtained as a brown solid (231 mg, 32%); 1H NMR (500 MHz, CDCl3) δ 8.71 – 8.60 (m, 1H), 7.93 (d, J = 8.2 Hz, 1H), 7.29 – 7.16 (m, 2H), 7.02 (d, J = 8.1 Hz, 1H), 6.80 (d, J = 7.4 Hz, 1H), 4.89 (s, 2H).
General Description
8-Aminoquinoline fluoresce moderately to weakly in low dielectric media but not in strongly hydrogen-bonding or acidic aqueous media. The reaction of 8-aminoquinoline with chromium (III), manganese (II), iron (II) and (III), cobalt (II), nickel (II), copper (II), zinc (II), cadmium (II) and platinum (II) salts has been studied.
Purification Methods
8-Aminoquinoline crystallises from EtOH, ligroin, octane or H2O, and complexes with metals. [Beilstein 22 III/IV 4708, 22/10 V 316.]
