Preparation of 5-amino-2- (2-hydroxyethylamino) -phenyl (2-hydroxyethyl) sulfone

摘要

The method for preparing the sulfone of formula (1) comprises reducing degradation of the disazo / disazooxy dye of formula (5).; (One); (5);In the above formula,;B is a direct bond or crosslinker,;v, w, x and y are each independently 0 or 1,;At this time, the sum of x and y is 0 or 1 and the sum of v and w is 0 or 1.