| 摘要 |
<p>A method for preparing a compound of formula (6), wherein said method comprises the steps of: alkylating a compound of formula (1) resulting into a compound of formula (2); wherein E is a C1-6alkyl; reacting compound of formula (2) with a sulfonation agent, resulting in a compound of formula (3); wherein LG is a leaving group; and coupling compound of formula (3) with a compound of formula (5). wherein PG is a protecting group; and wherein R2, R3, and R4 are as defined in the description.</p> |
