title: Convenient synthesis of 2,3,9,10-tetraoxygenated protoberberine alkaloids and their 13-methyl alkaloids.
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 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.
authors.affiliation: Faculty of Pharmaceutical Sciences, Kanazawa University, Japan.
authors.forename: M
authors.initials: M
authors.lastname: Hanaoka
authors.forename: T
authors.initials: T
authors.lastname: Hirasawa
authors.forename: W J
authors.initials: WJ
authors.lastname: Cho
authors.forename: S
authors.initials: S
authors.lastname: Yasuda
mesh_terms: 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
chemical_list: D000470:Alkaloids; D007202:Indicators and Reagents; D001599:Berberine