Many chemistry databases may be searched by substance and/or by reaction. Each database handles this function differently but the principles are the same.
There are a variety of ways to search the chemical literature. Search for substances or reactions using a chemical identifier or by drawing the chemical structure or substructure. Below are some videos and help resources on searching for substances in various databases.
SciFinder
Structure searching videos. Short videos on topics such as:
Training materials - videos by topic and overview materials
Reaxys
ChemSpider
Help page includes text & videos on search about using ChemSpider:
Chemical Name: Chemicals can have dozens of synonyms. Common types of chemical names include:
e.g. ibuprofen
e.g. Advil
e.g. 2-(4-isobutylphenyl)propanoic acid
e.g. list of synonyms for ibuprofen
Molecular Formula: Be careful using molecular formula to search; many substances have the same molecular formula.
e.g. C13H18O2
CAS Registry Number: CAS Registry Numbers are unique chemical identifiers. CAS Numbers are proprietary identifiers maintained by Chemical Abstact Services (CAS), makers of SciFinder. Many chemistry databases make use of CAS Numbers.
e.g. 15687-27-1
Wikipedia/Common Chemistry: This Wikipedia/CAS collaboration is handy for finding identifiers for common chemicals.