Lucent360™ Case Study:
Scaling Up: 100 mL reaction in the Lucent360™
The following reaction was performed at 100 mL scale (5 mmol) with the Lucent360™ batch reactor (HCK1021-01-007) at 450 nm equipped with nitrogen inlet/outlet ports, a septum for syringing in reagents/sampling and a temperature probe. (see photo above) The reaction is cooled by an external chiller set at 25 °C. For scaling up the reaction, the concentration of the iridium catalyst was reduced by 10% from 1 mol % to 0.1 mol % from the corresponding 2 mL reaction.
The 100 mL reaction was performed according to the following protocol (Table 1):
In the 700 mL Lucent 360 reactor, was added 54.9 mg Ni-glyme (5 mol %, 250 µmol), 67.1 mg dttbpy (5 mol %, 250 µmol) and 2.44 g Cs2CO3 (1.5 equiv., 7.5 mmol. To the reactor was a 100 mL solution in DMSO containing 0.995 g bromoacetophenone (5 mmol) and 1.63 g Boc-Val-OH (1.5 equiv., 7.5 mmol). 5.61 mg Ir(dF-CF3-ppy)2(dtbbpy) (0.1 mol %, 5 µmol) was added as a 1 mL solution in DMSO. The resulting solution was sparged with nitrogen for 15 minutes prior to turning on the LED’s and with a constant stream of nitrogen during the reaction. The reaction was performed at 30 °C in the Lucent360™ with 5- 450 nm LED modules at 100% intensity. Analytical samples were taken from each vial at 1,2 and 4 hours for analysis by LC-MS (10 µL dilution to 1 mL in DMSO.
At 1 hour, starting bromoacetophenone was completely consumed and 81% of the expected product was determined by LC-MS.
|Reagent||Equivalent||Amount (µmol)||Amount (mol)||0.001||M|
Actinometry experiments with 100 ml reaction in the Lucent360™ have determined an effective power of 40 W in the reactor. This corresponds to a photon flux in the reactor at 150×10-6 einstein/s. This value represents 150×10-6 moles of photons per second in the 100 mL reaction.
Based on our 81%, we estimated that 0.004 mol was produced in 60 minutes (3600 s) (1.13×10-6 mol/s) and the resulting quantum yield of the reaction would be 0.007.