The invention provides p-iodoaniline and a preparation method thereof, and belongs to the technical field of
organic synthesis. A purpose of the invention is to solve the problems of excessive elemental
iodine consumption and increased three wastes caused by a large amount of
sulfate generated by reaction in the existing p-iodoaniline preparation method. The method comprises: 1, adding
aniline andwater into a first reaction container according to a certain ratio, adding elemental
iodine into the first reaction container in a dropwise manner, stirring to prepare a first solution, cooling the first solution to 0-20 DEG C, adding
hydrogen peroxide with a
mass concentration of 30% in a dropwise manner, and carrying out sampling analyzing until the
mass percentage content of
aniline is less than 0.5% to obtain a second solution; 2, adding
sodium sulfite into the second solution, stirring for 0.4-0.5 h to obtain a third solution, and carrying out suction
filtration on the third solution toobtain a brown
crystal; and 3, pouring the brown
crystal into a second reaction container, and carrying out
extraction purification treatment to obtain the p-iodoaniline finished product. According tothe invention, with the method, the consumption of elemental
iodine is low, the crude product content is high, and the generation of
sulfate is avoided.