[JonathanS]

My goal is to make a library of organic molecules. As I would assume all of the common chemicals all have CAS numbers, I thought searching all CAS numbers was the best approach.

I know the lowest CAS number is 50-50-0, but how do I find the next one in the list?

I tried searching 50-51-1 at http://www.sigmaaldrich.com/chemistry.html but I got no result.

What is the next CAS number after 50-50-0 and how do I find the next one after that, so on and so forth?

Thanks!

[Fluorine]

This might help answer your question; CAS registry number format (wiki)

[Borek]

You may want to check with Chemical Abstracts Society about legality of your plans:

A User or Organization may include, without a license and without paying a fee, up to 10,000 CAS Registry Numbers or CASRNs in a catalog, web site, or other product for which there is no charge. The following attribution should be referenced or appear with the use of each CASRN: CAS Registry Number is a Registered Trademark of the American Chemical Society.

I am more than sure CAS/ACS has a database of all CAS numbers.

[JonathanS]

Also from my post I'm sure it is clear I understand the format.

I was right, but had to go to the right place to find it (http://chem.sis.nlm.nih.gov/chemidplus/).

It was a bit surprising I had to search around for something you would think would be easier to find.

I'll look into the legality.

Thanks!

[Arkcon]

My goal is to make a library of organic molecules. As I would assume all of the common chemicals all have CAS numbers, I thought searching all CAS numbers was the best approach.

Not really.  Every substance that someone has asked Chemical Abstracts Services to index has a number.  There are many experimental substances with no number.  There are certainly redundant numbers, someone has simply asked CAS for a number, and they assign one.  People have definitely given mixtures to CAS and gotten numbers assigned.  You're correct that all common chemicals have a number, but searching sequentially may not be the best approach.

[JonathanS]

What would you suggest then?

The only other approach i can think of is to get a library of every organic chemical that Aldrich supplies (150k+).

Question is, does Aldrich supply every single cheap molecule?

[fledarmus]

What are you trying to accomplish?

There are already databases of commercially available organic compounds which number in the millions. These have been assembled by many of the providers of virtual screening services, which have a business model involving calculating the entire database against a computer model of a target enzyme and then supplying the best of those compounds for in-house screening. Many of them will also provide primary screening services.

There are also services like eMolecules.com which provide a platform for chemical suppliers to connect with researchers. They have a database of over 5 million commercially available compounds.

And if it is simply a question of searching for CAS numbers, Chemical Abstracts Services provides their own search tools in SciFinder.

If you are trying to make a new list, it would help if you could give a little more information on exactly what purpose your list would be serving.

[JonathanS]

Ah sorry, forgot to mention that sense I though the CAS number was the solution.

My objective is to collect all organic molecules which come from raw materials (oil, etc) with little to no processing. I say as little as possible because I know that oil and other raw materials start out with very long chains of carbons which are broken down into smaller ones.

Essentially if my goal was to get isopropyl alcohol, I wouldn't just buy isopropyl alcohol because it would be more expensive. I would get propene (which is a result of cracking larger oil molecules) and hydrating it.

I know that simpler molecules does not necessarily mean it is cheaper. But from a logical point of view (correct me if i am wrong) the closer a molecule is to its raw material the cheaper it will be.

And that is my goal, create a library of molecules which are very close/are the raw material.