You can used the refrence attashed file

Thank you

Dear Mahmoud,

First, convert the indole carboxylic acid to the corresponding acyl chloride derivative using oxalyl chloride, thionyl chloride or etc. Second, attach your alkaloid (N-) to the acyl chloride to form the amide of indol-alkaloid. The final step is reduction of the amide group of indol-alkaloid to the corresponding amine by any appropriate reducing agent.

Hoping this will be helpful,

Rafik