under the condition of the ice, to 1000 ml three port successively added in the bottle KOH (58.35g, 1 . 16eq, 1 . 04mol) and 585 ml water, the reaction system is cooled to 0 °C, adding to the reaction system (103.61g, 1eq, 0.892mol), after stirring at room temperature add 24h; once again the reaction system is cooled to 0 °C, in the reaction system by adding NaNO2(71.76g, 1 . 16eq, 1 . 04mol), the reaction system to maintain 0 °C, to wherein the dropwise H2SO4(50%), the for PH 4-5 (adding sulphuric acid to the volume to the final system is PH), stir at room temperature 2h, this will produce a large amount of gas in the process, a white precipitate, then in to the system by adding NaOH (35%) solution, the for PH 9-10, finally in the reaction system by adding 100 ml of toluene, the organic phase and aqueous phase separation, is added to the aqueous phase H2SO4(50%) the adjusted to PH 5-6, ethyl acetate (3*100 ml) extraction, anhydrous sodium sulfate for drying, can be obtained turns on lathe does white solid 61 . 3g (yield 79%).
