The invention relates to a process for the preparation of a compound of formula I (I), wherein R1 is hydrogen, fluoro or chloro; which process comprises a) reacting a compound of formula II (II), wherein R1 is hydrogen, fluoro or chloro; with a nitration agent to the compound of formula (III), wherein R1 is hydrogen, fluoro or chloro; and b) reacting the compound of formula III with chlorine gas at temperature from 180°C to 250°C to the compound of formula I.
本发明涉及一种制备公式I(I)化合物的方法,其中R1是氢、
氟或
氯;该工艺包括a)将与公式II(II)的化合物,其中R1是氢、
氟或
氯;与硝化剂反应得到公式(III)的化合物,其中R1是氢、
氟或
氯;以及b)在180°C至250°C的温度下,将公式III的化合物与
氯气反应得到公式I的化合物。