We used a subset of the Enamine building block catalog global stock as the set of commercially available reactants by which virtual molecules are synthesized . This set, consisting of 150K unique building blocks, was narrowed down by Gottipati et al. . to those applicable to one or more rules in a template-based reaction prediction model. The design task was to identify the synthesizable products in this reactant set and to meet the required properties. The Enamine reactant set was also used to train the GTM model as well. Each reactant was transformed into a binary vector of length 3239 concatenated with the Morgan fingerprint of radius 2 and bit length 1024, the MACCS key, and the RDKit fingerprint. A total of 441 predefined clusters were used in the similarity-based SMC proposal.