Convenient synthesis of 2, 3, 9, 10-tetraoxygenated protoberberine alkaloids and their 13-methyl alkaloids.

M Hanaoka, T Hirasawa, WJ Cho…

Index: Hanaoka, Miyoji; Hirasawa, Taeko; Cho, Won Jea; Yasuda, Shingo Chemical and Pharmaceutical Bulletin, 2000 ,  vol. 48,  # 3  p. 399 - 404

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Citation Number: 8

Abstract

New and convenient synthesis of 2, 3, 9, 10-tetraoxygenated protoberberine alkaloids and their 13-methyl alkaloids through the same intermediates was developed. Acylation of the brominated benzylphenethylamine (13) with α-chloro-α-(methylthio) acetyl chloride, followed by cyclization with stannic chloride, furnished tha key intermediates 4-methylthio-3- phenethylisoquinolin-3-ones (14), which were methylated to provide their methyl ...