Using direct condensation method meconin with isoquinolinium isodid salt, the authors had synthesized of bicuculin by a new method. With this method, an important intermediacy - erythro cordrastin isomer - was created with the greater rate in comparison with threo isomer. Two isomers were separated easily due to silicagel chromatography. The erythro isomer was demethylated by BBr3 reagent. Methylenation of tetrahydroxy compound provided bicuculline racemic. Separate the contrasts of bicucullin racemic by acid D (+) could help to obtain (+) bicucullin with high optical purify which were reached standards for next biological tests
Pharmaceutical Preparations ; Chromatography

Phthalideisoquinoline alcaloid norbicuculline have been synthesized by Bischler-Napieralski cyclization. The racemic norbicuculline were resolved into (+) and (-) forms. Methylation of (+ )norbicuculline provided (+)bicuculline. Researching bicucullin synthesis by the method of Bischler – napieralski shows that bicucullin is synthesized from Piperonal and Beta - (3,4 methylendioxy) – phenylethylamin by method of Bischler – napieralski. Isomers of ( ±) erythro and (±) threo norbicucullin are easily separated thank to nhờ sắc kí cột silicagel. Afterwards, optical isomers of (±) norbicucullin are also separated with high optical purity and good output. Methyl changed into (+) erythro norbicucullin is to gather (+) bicucullin gaining standards for biological experiments
Bicuculline ; Pharmaceutical Preparations