A method for preparing a compound of formula (III):
wherein:
R1, R2, R3, R4, R5, R6, R7, R8, L, Z and p are as defined in the specification;
said process preferably comprising either a noble metal catalyzed hydrogenation or a non-catalytic reductive ring closure of an azo dye compound of formula (IV):
where R11 is as defined in the specification, thereby performing a reductive ring closure and selective O-deacylation in a single process step.
一种制备式(III)化合物的方法:
其中
R1、R2、R3、R4、R5、R6、R7、R8、L、Z 和 p 如说明书中所定义;
所述工艺最好包括式(IV)偶氮
染料化合物的贵
金属催化氢化或非催化还原闭环:
其中 R11 如说明书中所定义,从而在一个工艺步骤中完成还原性闭环和选择性 O-脱酰基。