Scaling-out pharmaceutical reactions in an automated stop-flow microwave reactor

Six pharmaceutically relevant reactions were assessed for scale-out in an automated stop-flow microwave reactor. Daily throughputs of between 50 and 250 g were achieved at typical reaction concentrations; for more concentrated reactions, or with 24 h processing, productivity of 0.5-1.5 kg per day was achievable. This study confirms that the stop-flow approach in combination with rapid microwave heating can be equivalent to conventional continuous flow technology with comparable productivities.