合成路线1

Oxidation of 5-hydroxy-5,6,7,8-tetrahydroisoquinoline (I) using CrO3 in pyridine produced the corresponding ketone (II). Subsequent condensation of (II) with methyl cyanoformate (A) in the presence of lithium hexamethyldisilazide gave ketoester (III), which was reduced to hydroxyester (IV) by means of catalytic hydrogenation. Dehydration of (IV) to the unsaturated ester (V) was achieved by treatment with methanesulfonyl chloride and triethylamine, followed by basic elimination with DBU. Saponification of the ester group of (V) produced carboxylic acid (VI). After activation of (VI) as the mixed anhydride (VII) with isopropyl chloroformate (B), coupling with tryptamine (VIII) furnished the title amide, which was finally isolated as the hydrochloride salt.