Synthesis and structural characterization of 2-(2,5-diamino phenyl)ethanol

Nitration of 3-fluorophenyl acetic acid(1) was accomplished by heating it to 70 ℃ with nitro-sulfuric acid in dichloroethane for 4 h and 5-fluoro-2-nitrophenyl acetic acid(2) was obtained with 67.8% yield.The obtained compound(2) was treated with borane-tetrahydrofuran(B2H6–THF) complex under nitrogen atmosphere in excessive THF for 18 h to give a kind of dark brown oil,followed by ammonolysis with NH3.H2O in autoclave at 100 ℃ for 6 h to produce 2-(5-amino-2-nitrophenyl) ethanol(3) in 84.4% yield.Catalytic hydrogenation of(3) under 0.6～0.7 MPa.over 10% Pd/C in anhydrous isopropyl alcohol at 70～80 ℃ for 12 h produced 2-(2,5-diamino phenyl)ethanol(4) with 64% yield.Compared with the method reported in literature,the overall yield of target molecule(4) was increased by 11%.The chemical structure of(4) was determined by HPLC-MS and 1H-NMR.