SciFinder is a web-based program used to access selected Chemical Abstracts Service (CAS) databases plus Medline. Once you have created a SciFinder account, you may also use SciFinder Mobile to access SciFinder databases with web-enabled smartphones.

License: 7 simultaneous users. Please log off when you complete your work.

System availability (U.S. Central Time): Sunday 00:00 until Saturday 21:00. On the first Saturday of each month, SciFinder will only be available until 16:00 and will not be accessible again until 00:00 the following day (Sunday).

New with SciFinder:

Databases and Full-Text Links

See CAS Content at a Glance:
See STN Database Summary Sheets:

CAPlus - updated weekly

  • 1907-present plus >110,000 pre-1907 journal and patent references (JACS 1879+, J. Phys. Chem. 1896+, J. Chem. Soc. 1878+ , & landmark papers 1900-1912). Preparation role (PREP) assigned 1907+. All other "roles" assigned 1967+.
  • Comprehensive – all areas of chemistry and chemical engineering – (analytical, applied chemistry, biochemistry, chemical engineering, macromolecular, organic, and  physical)
  • International coverage
  • Document types:  journals, patents, reports, conference proceedings, books, dissertations
  • Bibliographic information + abstracts (most records) + indexing

CAS Registry - updated daily

  • Chemical structure and dictionary
  • Mostly covers substances identified from the scientific literature from 1957 to the present with some classes (fluorine- and silicon-containing compounds) going back to the early 1900s.
  • >56,000,000 organic and inorganic substances, and >62,000,000  sequences.

CAS Reacts - updated weekly

CAS Reacts contains chemical reaction information derived from documents indexed in a number of sources.
  • >43 million single- and multi-step reactions
  • Journals covered in the Chemical Abstracts Organic, Organometallic and Organometalloid Sections from 1985 to the present; indexes synthesized reactions from the examples contained in the articles, i.e., reactions which have experimental procedures and products with some kind of data (yield, m.p., etc.) Compounds mentioned in the examples which have no data of any kind are not indexed in CAS REACT.
  • Patents covered in the Chemical Abstracts Organic, Organometallic and Organometalloid Sections from January 1991 to the present.
  • The reaction collection jointly built by the All-Union Institute of Scientific and Technical Information of the Academy of Sciences of the USSR (VINITI) and the German Zentrale Informationsverarbeitung Chemie, Berlin (ZIC) and supplied by the German software company, InfoChem (journals 1974-19919 patents 1982-1999)
  • Rxn: Core Reactions database from the French organization, INPI (Institut National de la Propriete Industrielle) (1840-1985)
  • Biotransformations database compiled during the years 1971-1997 under the direction of Professor Doctor Klaus Kieslich
  • Wiley reaction collection (Encyclopedia of Reagents for Organic Synthesis)

CHEMCATS - updated when new or revised information is available

  • Catalogs and chemical libraries, 2007 to the present
  • >44 million commercially available chemicals
  • >1100 suppliers
  • >1200 catalogs
  • Record contains catalog information for the substance e.g., chemical and trade names, the company names and addresses, and supplier information

CHEMLIST - updated weekly

  • Domestic and international regulatory information from America, Asia, and Europe.
  • Over 275,000  chemical substances on national and international chemical inventories and regulatory lists.
  • Records contain substance identity information, inventory status, source of information, and summaries of regulatory activity, reports, and other compliance information.

Medline (1946 – date)

Full-Text Links - ChemPort Connection

  • Links to full-text electronic journals
  • ChemPort may take you directly the article or open an intervening browser window.
  • Always check Find It or MadCat for the most accurate electronic journal information.

Full text link in CAPlus record


The EXPLORE function you choose determines the database searched.

  • Explore References searches CAPlus and Medline. Substance registry numbers in the records link to CASRegistry.
  • Explore Substances searches CAS Registry. CASRegistry records link to records in CAPlus, Medline, ChemCats, CAS Reacts and ChemList.
  • Explore Reactions searches CAS Reacts. CAS Reacts records link to records in CAPlus and substances records in CASRegistry.


  • Last name required.
  • Use first initial or first name to retrieve list of entires in the databases.
  • Check Look for alternate spelling of the last name.
  • Select author candidates with first initial AND first name. (Chemical Abstracts' policy is to index author's name as it appears in original publication.)

Example: Theodore W. Richards' 1910 article in a physical chemistry journal


Search Type Example
  • Single components filter
  • Me shortcut
  • Answer set can include stereoisomers, isotopic variants, and multicomponent substances where the exact structure is one of the components, despite filters.
  • For more precision, select Show precision analysis and choose Conventional Exact candidates from the list.
Exact structure drawing
  • Lock out ring fusion or ring formation.
  • Lock out further substitution at position.
  • Atom Menu Tool – Halogens “X”
  • R Group - R1 defined as C, O, N, S, H
  • ANALYZE by Element
  • REFINE by property value
Substructure search drawing
Variable Attachment
  • Node or fragment attached to any of several positions on a ring system
  • Some restrictions apply
Varial attachment drawing
  • Based on Tanimoto score
  • Locates structures that are similar to your query in descending score
  • Scores computed on several structure descriptors
similarity search drawing
Repeating Group
  • Specify node or group of nodes in a structure to be repeated.
  • Some repetition range restrictions.
Repeating group

Variable Attachment Position tool

  • Specify a node or fragment and attach it to any of several positions on a ring system for searching.
  • One or more substituents can be variably attached to the same nodes in the ring system.

Substituent node:

  • Can be single node or a node in a larger fragment
  • Can be (or contain): element, variable, shortcut, R-group (with no additional attachments), repeating group
  • Can be locked to further substitution
  • Cannot be part of repeating group,
  • Substituent for one variable attachment position cannot contain the ring attachment positions for a separate variable attachment position.
  • Cannot have variable attachments to more than one ring system.

Variable Attachment Node:

  • Can be non-metal or X, Q, or A.
  • Can be locked to further substitution.
  • Cannot be a shortcut, a metal atom, M, Ak, Cb, Hy, or Cy
  • Repeating group cannot contain the ring attachment position ofr a separate variable attachment position.

Variable Attachment Bond that attaches substituent to ring:

  • Always a chain bond – cannot be modified.
  • May have any value: single, double, triple, or unspecified.
  • Cannot be a stereo bond.

Repeating Group

The Repeating Group tool allows you to specify that a node or group of nodes in a structure can be repeated.
  1. Click on the node to be repeated and specify repetition range. Some restrictions.


A Markush search matches generic structures referenced in patents. The result is a list of patent documents from CA Plus 1988 – present and derived from Institute National de la Propriete Industrielle (INPI) data from 1961 to the present

Similarity Searching

  • Based on Tanimoto score.
  • Locates structures that are similar to your query
  • Scores computed based on these kinds of structure descriptors:
    • Atom count
    • Ring count
    • Atom sequence
    • Bond sequence
    • Augmented atoms
    • Degree of connectivity
    • Element composition
    • Type of ring fusion


  1. Draw reaction query.
  2. Use Reaction Arrow or Reaction Role to assign roles to the reaction participant(s).
  3. (Optional) Apply Reaction Classification filters.

All substances in the reaction results are hyperlinked to other reaction, substance information, and references. Reaction results can be viewed as individual steps in a multi-step reaction or one reaction per reference.

Half-reaction drawing

Hover over structure or reaction drawing for more options, such as send to SciPlanner.

Research Topic

Search tips:

  • Compose search using two or three concepts combined with prepositions, conjunctions, and other simple parts of speech
  • Do not use the word AND or OR if a preposition would be more exact
  • Distribute modifiers
  • Place synonyms in parentheses next to the topic
  • System uses “natural  language” instead of Boolean operators for searching
    • Concepts separated by prepositions or stop words
    • Impossible to see exact search statement

    Example: biomimetics of the extracellular matrix

  • Specify two or three concepts separated by prepositions such as after, among, at, between, from, in, into, of, on, upon , with , and within . Do not use the Boolean operators AND and OR if a preposition would be more exact.

    Example: preparation of vitamin d analogs for cancer treatment (retrieve references associated with Adverse Effects, Biological Studies, or Preparation roles)

  • Use quotations to specify phrases.
  • Add synonyms in parenthesis following the related term.

    Example: dyes in "over the counter" (OTC)

  • Distribute modifiers among terms separated by OR.

    Example: solvents for protein folding or protein renaturation

  • If your search is complex with multiple concepts and several synonyms, begin with one or two concepts and their synonyms. Use REFINE by Research Topic to add additional concepts. Other uses of Refine include document type (Patents, Reviews) and Publication Year.
  • Use ANALYZE to identify relevant authors, CA Section Title, Indexing Terms. Note that CA Section Titles are Chemical Abstracts- specific and will eliminate Medline records.
  • Use CATEGORIZE to contextualize results.
  • For more help, see:

Note: When searching for clinical drug information, use a combination of text words and MeSH terms in PubMed. Then limit by terms/publication types that bring up more valid clinical studies or systematic reviews. If you are looking for substance information for clinical trials drug development, etc. search Medline via the PubMed interface  and SciFinder. Registry Numbers in PubMed/Medline have not been included for the past ten years. They were obtained from CAS prior to that time.

Viewing Results

Analyze - creates a temporary focused view of the current answer set; does not create a new answer set: click Show More to alphabetize.

Refine - returns a subset of the current answer set using selected criteria.

Categorize - (“below the fold”– don’t miss this!) limits the current answer set to results associated with index terms grouped by science category (contextualizes results).

Get Related (for individual reference or a selection of references)

  • Citings - retrieves document references that cite the record(s): CAPlus records 1997-present; Medline – only those Medline records cited by records deposited in PubMed Central
  • Substances - retrieves CAS Registry substances indexed in the record(s)

Use Combine Answer Sets to combine a current answer set and one or more saved answer sets.

Save/Export Answer Sets

  • Use Save to save answers to the CAS server. Access saved answer sets in your account workspace.
  • Use Export to save copy of an answer set or individual answers locally. Export formats vary depending on the type of answer set. Use Citation export format (.ris) or Tagged Format (*.txt) for Endnote or other citation manager.
  • Keep Me Posted (KMP) creates a profile based on a previously executed search query. The query is re-executed weekly or monthly. You receive an email notification after each run and can view the results after you sign in to SciFinder.