METHOD AND APPARATUS FOR THE SYNTHESIS OF DIHYDROARTEMISININ AND ARTEMISININ DERIVATIVES
First Claim
1. A method for reducing artemisinin in a continuous manner comprising the following steps:
- 1) providing a column containing a hydride reducing agent, at least one activator and at least one solid base or providing a first column containing at least one solid base and a second column containing a hydride reducing agent and at least one activator,2) providing a continuous flow of a solution of artemisinin in at least one aprotic solvent containing at least one C1-C5 alcohol through the column containing the hydride reducing agent, the at least one activator and the at least one solid base or through the first column containing the at least one solid base and the second column containing the hydride reducing agent and the at least one activator,3) thereby reducing artemisinin in a continuous manner to dihydroartemisinin of the following formula
1 Assignment
0 Petitions
Accused Products
Abstract
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.
2 Citations
15 Claims
-
1. A method for reducing artemisinin in a continuous manner comprising the following steps:
-
1) providing a column containing a hydride reducing agent, at least one activator and at least one solid base or providing a first column containing at least one solid base and a second column containing a hydride reducing agent and at least one activator, 2) providing a continuous flow of a solution of artemisinin in at least one aprotic solvent containing at least one C1-C5 alcohol through the column containing the hydride reducing agent, the at least one activator and the at least one solid base or through the first column containing the at least one solid base and the second column containing the hydride reducing agent and the at least one activator, 3) thereby reducing artemisinin in a continuous manner to dihydroartemisinin of the following formula - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 15)
-
-
11. A continuous flow reactor for the continuous production and reduction of artemisinin comprising:
-
a photochemical reactor for performing the photooxidation of dihydroartemisinic acid with singlet oxygen in a continuous manner, a reactor for performing an acid mediated cleavage of the photooxidation product and the subsequent oxidation with triplet oxygen in order to obtain artemisinin, a column containing a hydride reducing agent, at least one activator and at least one solid base or a first column containing at least one solid base and a second column containing a hydride reducing agent and at least one activator in order to obtain dihydroartemisinin. - View Dependent Claims (12, 13, 14)
-
Specification