A comparison of batch with continuous experiments reveals that the yield of the desired Grignard reagent 5 was always greater in the continuous experiments. The best results obtained with the batch synthesis are similar to the worst results obtained with the continuous approach. By using a continuous synthesis process, the fraction of 6 can be reduced, the quality of the product obtained is improved and the efficiency of the synthesis is increased. The positive effect of a continuous synthesis process on the production of Grignard reagents is thus clearly demonstrated (figure ). For the fine magnesium turnings, the Bo obtained by displacing the toluene from the reactor system were used, whereas for the coarse magnesium turnings, the Bo obtained by introducing the tracer toluene were used. This selection was made based on the Bodenstein numbers obtained when using a mixture of coarse and fine magnesium turnings (see part 1 for details), since the magnesium bed in the steady-state of a Grignard synthesis resembles a mixture of coarser and finer magnesium turnings due to the reacting magnesium. Assigning a Bodenstein number of 0 to the batch synthesis enables to evaluate the impact of the residence time distribution on the selectivity towards the Grignard reagent. A linear correlation is found for both sizes of Mg turnings, indicating that a further improvement in Bodenstein numbers could lead to a further increase in selectivity.