CHEM 324 - Using the Chemical Literature in an Organic Synthesis

There are common problems you may encounter when navigating the chemical literature:

• Not all of the information available on the over 30 million unique substances now registered with Chemical Abstracts Service (CAS) is found in one resource.
• A chemical can have many common names and tradenames. CAS has introduced Registry Numbers (unique identifiers) for substances, but not all publishers or commercial suppliers use these.
• Search engines are a great resource but it is difficult to navigate through the amount of information even an advanced search reveals. When you do find something it is not easy to judge whether a website is accurate and authoritative. You may find that you often have to pay for good chemical information on the Internet.

SciFinder (Chemical Abstracts) is the most comprehensive resource for finding articles in chemistry with information on over 50 million substances and more than 18 million single- and multi-step reactions.

For finding synthesis information in SciFinder:

• Search for your compound by clicking on the Explore tab and selecting Substance Identifier from the dropdown menu. Once you've found your compound, click on the "References" link (the icon that resembles a small sheet of paper). Specify that you want references dealing with preparation;
  OR
• Search for your compound by clicking on the Explore tab and selecting Substance Identifier from the dropdown menu. Once you've found your compound, click on the "Reactions" link (the icon that resembles an Erlenmeyer flask). Specify that you want references where your compound is a product of a reaction;
  OR
• Search for your compound by clicking on the Explore tab and selecting Research Topic from the dropdown menu. In the search box, type "synthesis of" your compound name.

For more search tips see the SciFinder Introduction.

SciFinder is accessible from home, but you may be prompted for your netname and password.

• ChemIDplus: Dictionary of over 370,000 chemicals. Search by name, CAS RN, structure. On the results page, choose 'Physical Properties' under 'Basic Information' (in the left hand menu).
• ChemSpider: Locates chemical information from open access and commercial databases. It gives CAS Registry Numbers, synonyms, structures, and some properties (density, boiling point, melting point) for thousands of compounds.
• NIST Chemistry WebBook: Provides free access to chemical and physical property data of over 70,000 compounds. This database gives CAS Registry Numbers, synonyms, and structures and is an excellent source for finding spectral information.
• The Physical Properties Database (PHYSPROP): Retrieves data for 25,000 compounds. Must search by CAS RN. Physical properties provided include melting point, boiling point, water solubility, octanol-water partition coefficient, vapor pressure, pKa, Henry's Law Constant, and OH rate constant in the atmosphere.
• Organic Syntheses: This free resource provides detailed directions for the synthesis of organic compounds. Search all volumes of Organic Syntheses (from 1921 - today) simultaneously by keywords or structure.
• Methods in Organic Synthesis: Provides citations to reaction methods with a focus on current developments.

There is also a list of other databases you can try for literature searches.

Print sources give good summaries and provide physical property data, but can be hard to use. It is best to go to a database, such as SciFinder, to get the CAS-RN then go to a print source for more information.

The following reference books compiled the best data for the most often used chemicals:

• Dictionary of Organic Compounds : The entries will often include references to synthesis citations, alongside structure and physical property information.
• CRC Handbook of Chemistry and Physics: Contains a lot of information, including Physical Constants of Organic Compounds, and conversion tables. It also has definitions and nomenclature information.
• Merck Index: An Encyclopedia of Chemicals, Drugs and Biologicals: Provides data and related references for compounds having pharmacological properties. The Merck Index gives a good overview for each compound, some property data, and medical as well as non-medical uses of the compound.

See the Print Sources handout (PDF) for a printable version. Other handbooks as major sources of chemical data, or for specialized topics, are listed in the Sources In Chemistry & Biochemistry (PDF) and Sources In Organic Chemistry (PDF).