A High-Yielding Synthesis of EIDD-2801 from Uridine.

A simple reordering of the reaction sequence allowed the improved synthesis of EIDD-2801, an antiviral drug with promising activity against the SARS-CoV-2 virus, starting from uridine. Compared to the original route, the yield was enhanced from 17 % to 61 %, and fewer isolation/purification steps were needed. In addition, a continuous flow procedure for the final acetonide deprotection was developed, which proved to be favorable toward selectivity and reproducibility.

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.