Design and Performance Validation of a Conductively Heated Sealed-Vessel Reactor for Organic Synthesis

A newly designed robust and safe laboratory scale reactor for syntheses under sealed-vessel conditions at 250 °C maximum temperature and 20 bar maximum pressure is presented. The reactor employs conductive heating of a sealed glass vessel via a stainless steel heating jacket and implements both online temperature and pressure monitoring in addition to magnetic stirring. Reactions are performed in 10 mL borosilicate vials that are sealed with a silicone cap and Teflon septum and allow syntheses to be performed on a 2-6 mL scale. This conductively heated reactor is compared to a standard single-mode sealed-vessel microwave instrument with respect to heating and cooling performance, stirring efficiency, and temperature and pressure control. Importantly, comparison of the reaction outcome for a number of different synthetic transformations performed side by side in the new device and a standard microwave reactor suggest that results obtained using microwave conditions can be readily mimicked in the operationally much simpler and smaller conventionally heated device.