I refer you back to the original post from which this comment was made as it is taken from a specific context.

“There is no “right structure (sic)” for a compound. There are structures which have a very high probability of being associated with a name. There are names which have a probability of representing a chemical entity.”

Is this a true statement? In many case I would agree but I have my own opinion in specific cases and let’s focus on the drug industry for a moment and trade names. First, let’s talk about me..and my identifiers. Depending who’s talking about me I am Tony, Antony, Dr Williams, Mr Williams, Dad, sweetheart, son, Tone, AJ, Bro’ and so on. However I am registered with a social security number and exist as a legal entity, a “registered” entity.

Now, Zantac is a registered trade name for the chemical here. I am not an expert in the registration process but I believe that somewhere along the line a defined chemical entity is associated with that name. Whether the chemical entity has been appropriately elucidated by analytical technologies or not is a different question. What is registered as a compound, and associated with the name, is what that name defines.

Now, there are a whole series of other names for the same compound – registry numbers, systematic names, organization numbers. See below:

Ranitidine [Wiki]



1,1-Ethen​ediamine,​ N-[2-[[[​5-[(dimet​hylamino)​methyl]-2​-furanyl]​methyl]th​io]ethyl]​-N’-methy​l-2-nitro​-, (Z)-

128345-62​-0 [RN]

266-332-5 [EINECS]

66357-59-3 [RN]


GR 122311X







Ranitidin​e Base









I think that the Trade Name for a compound is definitive since its registered. Relative to the statement “There are structures which have a very high probability of being associated with a name. There are names which have a probability of representing a chemical entity.”…my question is whether a Registered Trade Name is absolute? I’m asking the question since I’m actually not sure. Thoughts anyone?

Stumble it!

2 Responses to “Is there 100% in chemical names and compounds?”

  1. Rich Apodaca says:

    Tony, you’d probably find agreement among chemists that a trade name uniquely identifies one specific chemical entity. Ditto CAS Number.

    But in practice (in databases, Excel spreadsheets, books, reviews, peer-reviewed articles, etc.), you’d find some disagreement about the structure that a particular identifier should be linked with, and vice-versa.

    The disagreements would range from the baffling (completely wrong structure) to the annoying (wrong stereochemistry) to the amusing (ionized carboxylate vs. protonated).

    For databases that aggregate content from diverse sources, the best practice may be to model this situation with a many-to-many relationship, rather than a one-to-one or even one-to-many.

    In other words, CAS numbers, trade names, and IUPAC names may be better modeled as social networking-style tags than as unique identifiers. I’m not saying this is the way things should be – just that this is how situation appears to have evolved.

    See this article, which discusses the problem as it applies to CAS numbers used in the wild and how Chempedia addresses it:


  2. Cdementor says:

    Is there 100% in chemical names and compounds?

    Every entity that exists in the nature has a name and a name is how we identify that entity. Semilarly, each chemical compound is identified by it’s name or names. Naming chemical compounds by IUPAC is long process. However, it does not mater which name or names the compound is assigned, it will be 100% that compound’s name or names.

Leave a Reply