  In this paper we present SynKB, an open-source, automatically extracted
knowledge base of chemical synthesis protocols. Similar to proprietary
chemistry databases such as Reaxsys, SynKB allows chemists to retrieve
structured knowledge about synthetic procedures. By taking advantage of recent
advances in natural language processing for procedural texts, SynKB supports
more flexible queries about reaction conditions, and thus has the potential to
help chemists search the literature for conditions used in relevant reactions
as they design new synthetic routes. Using customized Transformer models to
automatically extract information from 6 million synthesis procedures described
in U.S. and EU patents, we show that for many queries, SynKB has higher recall
than Reaxsys, while maintaining high precision. We plan to make SynKB available
as an open-source tool; in contrast, proprietary chemistry databases require
costly subscriptions.
