The invention provides a process for preparing a compound of formula (II):
and salts thereof where one of R' and R2 is C1-4 alkyl, the other is bromo and n is 3-5 which comprises reacting a compound of formula (III):-
where one of R3 and R4 is C1-4 alkyl and the other is hydrogen with an electrophilic brominating agent.
本发明提供了一种制备式 (II):
及其盐的工艺,其中 R' 和 R2 中的一个是 C1-4 烷基,另一个是
溴,n 为 3-5。
其中 R3 和 R4 中的一个是 C1-4 烷基,另一个是氢与亲电
溴化剂反应。