Reducing artemisinin to dihydroartemisinin useful for treating malaria involves feeding artemisinin into reactor under continuous flow conditions, then reacting it with reducing agent to form dihydroartemisinin and removing it from reactor

NOVELTY - Reducing (m1) artemisinin to dihydroartemisinin (DHA) involves feeding artemisinin into a reactor where it reacts with a reducing agent to form DHA, and removing the DHA from the reactor, where the method is carried out under continuous flow conditions. USE - For reducing artemisinin to dihydroartemisinin (DHA) (claimed) which is useful for treating malaria caused by infections of Plasmodium falciparum, and also for producing different artemisinin-derived drugs e.g. artemether, beta -arteether or artesunate. ADVANTAGE - In contrast to the prior art methods for producing DHA, in which artemisinin is reduced to DHA in a batch reaction, the present method is carried out under continuous flow in the apparatus. Advantageously, continuous flow results in a significant increase in both the conversion rate of artemisinin and the yield of DHA compared to that which is achieved in a batch reaction, allowing much higher levels of productivity to be achieved. Thus, the continuous method of the present method using the apparatus enables the selective production of the key intermediate, DHA, for artemisinin-based antimalarial drugs in a highly efficient manner. The present method is carried out at much higher temperatures, thus circumventing the need for cooling to low temperatures. Accordingly, the amount of energy needed using the method and apparatus is significantly less than that used in prior art reduction protocols. The method serves to reduce the residence time of the reactants in the reactor in order to achieve full conversion of the artemisinin into DHA; utilizes the biomass-derived solvent (2-MeTHF) which is particularly environmentally friendly and has been successfully employed to substitute tetrahydrofuran (THF) with low residence times. The reaction involving the reduction of artemisinin to DHA is exothermic, and thus generates heat in the reaction chamber. DETAILED DESCRIPTION - An INDEPENDENT CLAIM is included for a dihydroartemisinin (DHA) production apparatus for reducing artemisinin into dihydroartemisinin (DHA), comprising feeder for continuously feeding artemisinin into a reactor in which DHA is formed, and device for continuously removing the DHA from the reactor, where the reactor is a continuous flow reactor.