| 摘要 |
The present invention relates to a method for making a compound of formula (II):
comprising, allowing a compound of formula (I):
to react in the presence of a compound of formula R 1 SR 2 and a chlorine-containing reagent under conditions sufficient to make the compound of formula (II); wherein
R 1 and R 2 are each independently -(C 1 -C 20 )alkyl, -(C 3 -C 8 )cycloalkyl or -phenyl; and
R 3 is a protecting group. |
