Convenient synthesis of 2,3,9,10-tetraoxygenated protoberberine alkaloids and their 13-methyl alkaloids.
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 alpha-chloro-alpha-(methylthio)acetyl chloride, followed by cyclization with stannic chloride, furnished the key intermediates 4-methylthio-3-phenethylisoquinolin-3-ones (14), which were methylated to provide their methyl derivatives (17). Both isoquinolin-3-ones (14, 17) were easily transformed into protoberberine alkaloids (16) and their 13-methyl alkaloids (21) in good yield.
Hanaoka
M
M
Faculty of Pharmaceutical Sciences, Kanazawa University, Japan.
Hirasawa
T
T
Cho
W J
WJ
Yasuda
S
S
D000470:Alkaloids / Q000138:chemical synthesis*; D001599:Berberine / Q000031:analogs & derivatives / Q000138:chemical synthesis*; D002850:Chromatography, Gel; D007202:Indicators and Reagents; D009682:Magnetic Resonance Spectroscopy; D013058:Mass Spectrometry; D013055:Spectrophotometry, Infrared
D000470:Alkaloids; D007202:Indicators and Reagents; D001599:Berberine