A, in the reaction vessel being provided with agitator, thermometer, reflux condenser, Dropping funnel, add cerium chloride 0.16mol, 4-hydroxy 3-methoxybenzene ethanol solution 0.19mol, Klorvess Liquid 400-500ml, control mixing speed and exist 160-190rpm, rising solution temperature, to 60-65°C, is slowly added to 2-chloro-6-nitrobenzoyl acid solution 0.13mol, sulfurous acid Hydrogen potassium solution 200ml, raises mixing speed to 260-310rpm, back flow reaction 5-7h；
B, reduction solution temperature, to 15-19°C, separate out solid, filter, and add diammonium hydrogen citrate solution 150-in filtrate 180ml, concentrating under reduced pressure, separate out solid, filter, dehydrant is dehydrated, brine, and pyridine solution washs, ethyl acetate solution Middle recrystallization, obtains crystal 2-amino-6-chlorobenzoic acid (C7H6ClNO2).
