title: Fine tuning of a reported synthetic route for biologically active flavonoid, baicalein.
abstract: A modified procedure of a previous synthetic route for baicalein was developed in order to obtain more than ten grams of baicalein for in vivo test. There were several difficulties in applying the published experimental procedures for a large scale of synthesis. The modified synthetic work was successfully accomplished by reducing amount of strong Lewis acid in Fries rearrangement and using tetrabutylammonium iodide as an additive to speed up the demethylation reaction in refluxing HBr into completion.
authors.affiliation: Natural Products Research Institute, College of Pharmacy, Seoul National University, Seoul 110-460, Korea.
authors.forename: Sanghee
authors.initials: S
authors.lastname: Kim
authors.forename: Dae Won
authors.initials: DW
authors.lastname: Sohn
authors.forename: Youn Chul
authors.initials: YC
authors.lastname: Kim
authors.forename: Soon-Ai
authors.initials: SA
authors.lastname: Kim
authors.forename: Sang Kook
authors.initials: SK
authors.lastname: Lee
authors.forename: Hak Sung
authors.initials: HS
authors.lastname: Kim
mesh_terms: D002626:Chemistry, Pharmaceutical / Q000379:methods; D002855:Chromatography, Thin Layer; D003640:Dealkylation; D004365:Drugs, Chinese Herbal / Q000138:chemical synthesis*; D044950:Flavanones / Q000138:chemical synthesis*; D018054:Hydrobromic Acid / Q000737:chemistry; D009682:Magnetic Resonance Spectroscopy; D013058:Mass Spectrometry; D015394:Molecular Structure; D000644:Quaternary Ammonium Compounds / Q000737:chemistry; D015203:Reproducibility of Results; D013678:Technology, Pharmaceutical / Q000379:methods*; D013696:Temperature; D013997:Time Factors
chemical_list: D004365:Drugs, Chinese Herbal; D044950:Flavanones; D000644:Quaternary Ammonium Compounds; D018054:Hydrobromic Acid; C006680:baicalein; C009405:tetrabutylammonium