Building on the single-step iteration, three follow-up iterations were achieved with a total of 1696 multi-step targets, via a combined total of 6592 reactions, and a combined success rate of 57.51% (Fig. ). Iter 4.2 was the most complicated synthesis attempted on the OpenTrons OT-1 with 160 attempts of two by two-step routes being combined towards the final product with an overall 78% success rate (Fig. ). Iter 4.2 showed that it is possible to use relatively complex multi-step chemistry to yield significant fragment elaborations.