To enable evaluation of reaction routes with respect of a set of target parameters, such as overall yield, impurities, economy or greenness, knowledge of the complete reaction record is required. When all reaction participants (reactants, reagents and products) are known, the reaction completion is simply a problem of mass conservation, i.e. using linear algebra to balance the reaction with stoichiometric coefficients. However, this is not always the case for data records that are currently accessible in Reaxys ® , 1, * USPTO, or any other none-manually curated reactions databases. An example of Reaxys ® reaction data record is shown in Figure . Three main aspects of the reaction data are often missing in records today: 3 stoichiometric coefficients, reaction co-participants and integration of multiple reaction steps into a single reaction entry. Figure . An example reaction record (Reaxys ® reaction ID: 27812599) summarised from multiple literature sources. The reaction record shows only major reactants and products, while the reaction co-participants are missing. The reaction participants, which do not contribute to the carbon flow, may be recorded as reagents.