CAS Registry Numbers in Reaxys

Substances are identifiable in many different ways: Reaxys ID, INCHI, Smiles, chemical name etc. CAS registry number (RN) is a popular identifier and an area where we saw an opportunity to enhance their availability within Reaxys. While Reaxys contains many CAS RN’s, obtained mainly through a former collaboration with CAS (CAS/Elsevier mutual information exchange) many Reaxys structures do not contain a CAS RN. With the latest release we now offer a new feature that will enable you to retrieve CAS RN’s for Reaxys substances that didn’t have them before.

Request a CAS RN on a substance results page:

Substances for which we do not have CAS RN, now show a button ‘Retrieve CAS RN’ (H) which allows you to request a CAS RN.

• For substances where a CAS RN exists, the number is displayed alongside the 'CAS' icon (I)
• If a CAS RN does not exist for the substance or is not retrievable, then the message 'CAS RN Unavailable' will be shown (J)

Request a CAS RN using the view details icon:

You can request a CAS RN using the view details icon (summary view of information available for a substance) available throughout Reaxys for example in a reaction, preview or document results, providing access to the identifier seamlessly as you move around different types of information within Reaxys.

• Select 'view details' (K) icon will provide an overview of all available substance data including their identifiers:

  • A CAS RN is shown directly if available (L)
  • If a CAS RN is not available, then the message 'CAS RN Unavailable' will show

Additional details:

• CAS RN displayed without the CAS icon are retrieved directly from within Reaxys. These are available to you at all times and do not need to be requested with a button.
• Substances which do not have a CAS RN (CAS icon) will show a button to request the CAS RN.

  • All requested CAS RN are temporary and are only available for the length of an active session. After which they are removed from Reaxys.
  • Temporary CAS RN cannot be exported. There are no changes to export of existing CAS RN already available in Reaxys.
• TThe new 'Retrieve CAS RN' button is currently available for both Reaxys database and Pubchem (RCS to follow).