61 research outputs found
Method and apparatus for the synthesis of dihydroartemisinin and artemisinin derivatives
The present invention is directed to a method for continuous production of dihydroartemisinin and also artemisinin derivatives derived from dihydroartemisinin by using artemisinin or dihydroartemisinic acid (DHAA) as starting material as well as to a continuous flow reactor for producing dihydroartemisinin as well as the artemisinin derivatives. It was found that the reduction of artemisinin to dihydroartemisinin in a continuous process requires a special kind of reactor and a special combination of reagents comprising a hydride reducing agent, at least one activator such as an inorganic activator, at least one solid base, at least one aprotic solvent and at least one C1-C5 alcohol
Method and device for the synthesis of Artemisinin
The present invention is directed to a method for producing artemisinin having the formula (6) from dihydroartennisinic acid in a continuous flow reactor using singlet oxygen as well as to the continuous flow reactor for producing artemisinin
Continuous Synthesis of Artemisinin-Derived Medicines
Described is a continuous, divergent synthesis system which is coupled to
continuous purification and is capable of producing four anti-malarial APIs.
The system is comprised of three linked reaction modules for
photooxidation/cyclization, reduction, and derivatization. A fourth module
couples the crude reaction stream with continuous purification to yield pure
API
Continuous-flow oxidative cyanation of primary and secondary amines using singlet oxygen
Primary and secondary amines can be rapidly and quantitatively oxidized to the corresponding imines by singlet oxygen. This reactive form of oxygen was produced using a variable-temperature continuous-flow LED-photoreactor with a catalytic amount of tetraphenylporphyrin as the sensitizer. -Aminonitriles were obtained in good to excellent yields when trimethylsilyl cyanide served as an insitu imine trap. At 25 degrees C, primary amines were found to undergo oxidative coupling prior to cyanide addition and yielded secondary -aminonitriles. Primary -aminonitriles were synthesized from the corresponding primary amines for the first time, by an oxidative Strecker reaction at -50 degrees C. This atom-economic and protecting-group-free pathway provides a route to racemic amino acids, which was exemplified by the synthesis of tert-leucine hydrochloride from neopentylamine
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