The 
Summary
Chemical database is a dictionary of over 400,000 chemicals (names, synonyms, and structures).
ChemIDplus includes links to NLM and other databases and resources, including links to federal, state and international agencies. ChemIDplus Lite is designed for simple searching on name or registry. ChemIDplus Advanced helps users draw their own structures and perform similarity and substructure searches. ChemIDplus records are updated daily.