Merck Index:
This index focuses solely on substance, precursors, and feedstock chemicals of vital importance to the pharmaceutical industry. However, when you find an entry on your molecule of interest, it gives a TON of information, including references to the primary literature on the synthesis and medical uses of substances. It also includes a synonym index, to assist you in finding a substance which goes by many chemical and trade names. For example, ibuprofen would also be listed under Motrin and Nuprin in the synonym index. Very helpful!

Pros: Has much valuable data dealing with drugs and other commercially important substances. Usually includes reference to syntheses. Usually includes CAS registry number. Has all common, trade, and chemical names of substances listed in index.
Cons: Only as up to date as most recent edition. Does not provide entry into Chem Abstracts.

Aldrich Catalog:
Pros: Easiest to use. Cross-referenced to some other reference sources. Excellent formula Index. Usually has CAS registry number.
Cons: Since it is a catalog of chemicals for making substances, has very few "end products" like drugs listed.

Web Sources -accessible through course web site (http://s05.middlebury.edu/CHEM0242A/)

Chemfinder (http://chemfinder.cambridgesoft.com/):
Pros: Usually gives picture, formula of substance. Has web links to other resources. Free
Cons: Very limited number of compounds listed. Most common drugs listed, more esoteric drugs not listed. Web links more for doctors and regulatory agencies, not for organic chemists. Free version only good for a few clicks, then shuts you off for a while- its really trying to sell you an unlimited access "pay-to use" service.

Web of Science (accessible through course web site, or library web site)
http://isi10.isiknowledge.com/portal.cgi/wos
Pros: Only way to find out who is citing a specific article- this allows you to find out what work is being done in a field if you only have one, old paper - a unique way to literature search. Easy to search through key words. For example, inputting the phrase synthesis of xxxxx, where xxxx is the name of your drug, will often give you several synthesis references. Pricey - but already paid for by college for unlimited time usage.
Cons: Only a few users allowed at a time simultaneously. If you wait until the last minute to complete the assignment, you may not be able to get on when you want to! Only good for references after 1985 - may not be useful for drugs synthesized long ago, and no longer of active interest to synthetic chemists. Our version does not do structure or formula based searches.

Note: For the April 15 and April 29 help Sessions ONLY, use the following urls for the Web of Science:

http://access.isiproducts.com/sales

Scifinder:
Requires separate software, rather than a web site
This is the single most powerful searching tool in the chemical world. You can find anything with it. As with most exhaustive searching tools, the challenge is more how to limit the search than how to find anything
Pros: You can search based on almost anything, including inputting a chemical structure. This allows you to find information without dealing with nomenclature. It can also locate references with the CAS registry number, as well as all the usual author, title and subject methods which almost all databases use.
Cons: Only a maximum of two users per time at Middlebury and two other colleges. Sometimes hard to limit your search.

U.S. Patent office (http://patft.uspto.gov/netahtml/PTO/srchnum.htm)
References on the syntheses of many drugs are only available in the patent literature. Searching patents is very easy, if you have the US patent number. Patent numbers are readily available from Scifinder, Merck Index, or sometimes other sources. It is usually identified by US XXXXXXX ( where X is a number) Older patents have been scanned in, rather than in true electronic form, and may need some funky software to view, rahter than the industry standard ".pdf" form.

The CAS registry Number looks like this: [234-5847-1] or CAS 234-5847-1