PREPARATION OF DEMETHYLENECEPHARANTHINE AND ITS ANALOGOUS COMPOUND

PURPOSE:To obtain the titled compound, an alkaloid having useful pharmaceutical action, by reacting cepharanthine or its analogous compound with BCl3, followed by reaction with an alcohol. CONSTITUTION:A compound shown by the formulaI(R1 and R2 are H, lower alkyl), cepharanthine occurring in plants of the family Menispermaceae, etc. and its analogous compound, is reacted with BCl3 or its alkylsulfide complex. In the reaction, the 6 and 7 positions of the compound shown by the formulaI are changed through a group shown by the formula II into a group shown by the formula III or IV. The prepared compound is reacted with a compound shown by the formula R-OH (R is alkyl), to give the desired compound shown by the formula V. Both the reactions are preferably carried out in a water-free solvent such as chloroform, etc. under an inert gas flow.