The new ajmaline derivative possessing high antiarrhythmic activity was synthesised on the basis of alkaloid isolated from the raw material by means of biotechnological method. The mathematical modelling of the alkylation process was carried out by means of polyfactor regression analysis for the choice of synthesis conditions. It is known, that the alkaloid ajmaline, isolated from biomass of culture tissue of Rauwolfia, can serve as the basis for the development of highly effective antiarrhythmic drugs [1].