Photochemical Library Synthesis
Here we present our latest application note: Photochemical library synthesis.
Library syntheses are key to almost all new drug discovery programmes, but are complex, time consuming and often limited to thermally mediated reactions. This application note describes how an R-Series has been used with a UV-150 photochemical flow reactor to perform a photochemical library synthesis of compounds from a [2+2] photocycloaddition with ethene.
Photochemical library synthesis
We have demonstrated carrying out a photochemical library synthesis, enabling us to access otherwise forbidden transformations. We have overcome a number of challenges that would be faced carrying out this procedure in batch; typically, batch photochemical screening reactions take place on the 2-3 mg scale, here we present samples of 50 mg of product being produced, with a reaction time of just 30 minutes per product. Also significant is that we have been able to operate at 6 bar using an SF-10, which keeps as much ethene as possible dissolved and in contact with the reagents. In batch, the only option is to bubble the ethene through the solution. The SF-10 is not sensitive to particulates and was used to mitigate against the poor solubility of the product as it leaves the reactor. The library took 6 hours to produce 12 products in 50 mg quantities and was able to safely operate over night under the automated control of Flow Commander™.
Photochemical reaction optimisation
Once an interesting compound has been made, you’re going to want to make more; using the automated control of Flow Commander™, photosensitisers and reaction conditions were screened quickly, and the results used to produce grams of selected products in high purity and yield.
This application note describes:
- Rapid synthesis of a library of 12 [2+2] photo-cycloadducts in 50 mg quantities
- Rapid screening of a range of photosensitisers
- Optimisation and scale-up of two products to several grams scale