Oxygen → Qing Hau Sau

Participants

Reaction Steps

The feed was a solution of dihydroartemisinic acid at a concentration of 0.5 mol/L and the photosensitizer tetraphenylporphyrin at a concentration of 1 mmol/L in toluene (2.95 g dihydroartemisinic acid and 15 mg tetraphenylporphyrin, total volume 25 mL, volumetric flask). The feed was introduced at a flow rate of 1.25 mL/min and the oxygen flow adjusted to 5 mL/min. The solution of trifluoroacetic acid injected into the output stream of the photochemical reactor contains 1.93 mL trifluoroacetic acid filled up to 20 ml with toluene (1.25 M, volumetric flask). The output stream showed a conversion of 89% yielding 62% of the desired artemisinin with a selectivity of 70% (NMR of crude).

Provenance & Evidence