A method for preparing a compound of formula I
the method comprising treating a compound of formula d
with an iodination reagent, to form the compound of formula I, wherein R
1
, R
2
and R
3
are as defined herein.
一种制备式I化合物的方法,包括用
碘化试剂处理式d化合物,形成式I化合物,其中R1、R2和R3如本文所定义。