Yesterday's post on citing the patent literature prompts today's. I realize that if you're not used to reading the things, patents can be rather odd and daunting. But there are some rules to follow to let you get useful information out of them. That depends on what you're looking for, though.
If you're searching for preparations of particular chemical compounds, there's an awful lot of that available, although sometimes it's not easy to extract. What you'll probably want to do is skip directly to the experimental section. Ignore the description; ignore the claims - if you want to find out how to make Compound X, you won't find the details you're looking for there.
Problem is, the experimental section will not necessarily be laid out in a user-friendly manner. It doesn't have to be, and in fact, it's sometimes deliberately convoluted. The first thing to make sure of is that you're looking at a real experimental procedure. If it's written in the present tense, and/or with vague details ("A compound of Formula 1 is combined with a base, preferably a tertiary amine, and is heated to between room temperature and 100 degrees C. . ."), then you'd better keep turning pages. This is not what you're looking for. This is a generic or prophetic example, and doesn't necessarily have anything to back it up. Keep going until you hit real amounts of real compounds, and real spectral data. Patent applications, ones that expect to stand up, anyway, have to exemplify the compounds that they're claiming, and that takes real data.
If the patent is written with structures over each each experimental procedure, then your job is a lot easier. Often the preps will be in sequence, one intermediate leading to another, although they don't have to be. Keep paging through until you've found the compound you're after. If the compounds are named in the procedures, a text search for some part of the particular name can save you a lot of time, as can a search for the name of some reagent that you may have seen that the inventors used (from a SciFinder search, for example).
Keep in mind that the particular compound you're looking for may appear as part of a table. Often patents will be written with a detailed general procedure for a particular example, and then there will be a line like "Following this same protocol, the following examples were also prepared. . .", and a table. I know that you'd rather have a detailed individual prep (so would I), but these are still generally pretty reliable. You find this sort of thing for lists of amides or Suzuki coupling products, so it's not too bad.
The amount of spectral data you'll get will vary. Actually, the rule for a patent application is "The more, the better", so a good one will include NMR data, and whatever else they can think of. The minimum is the LC/MS retention time and a few ions, which isn't all that helpful, but satisfies the legal requirements, barely. (Taiwan and a couple of other countries will often balk at that sort of thing, but that doesn't become an issue for a few years).
If you're looking for evidence of new biology or mechanisms of action, that will be a bit trickier. This will show up in the claims, but claim can be structured in a rather Byzantine manner. As with the chemistry, though, if it's something really important, there will be data to back it up. Gels, sequences, purification procedures - all that has to be in there if the company is really serious. If all you can find is a line somewhere about ". . .may also be useful for X Disease" or "as an antagonist of Receptor Y", with no more details, then you can ignore that.
The data for specific compounds will vary quite a bit, too. Everyone likes the sorts of patents that list off the compounds and give you real assay numbers next to them. Unfortunately, many filings take the "A, B, C" approach, where they bin the compounds into a few activity classes. That at least lets you pick the more potent ones out from the lesser ones, but there's an even more egregious practice. That's where there's a description of the assay, ending with a line like "All of the compounds claimed showed activity of at least 10 micromolar under these conditions". That sort of stuff drives me crazy, and I really think it should be legally discouraged. I think that this is gradually disappearing from the world, and speed the day.
If you're looking for the best compound in the whole patent, playing "hunt the clinical candidate", well, that can be a fun game. Sometimes it's clear in the way the claim language narrows down to a handful of "most preferred" compounds. Sometimes you can infer it by going through the experimental section and noting when a bunch of 50-milligram procedures suddenly jump to 25-gram procedures (or more). But if a company really wants to hide their single best compound in a forest of other good ones, it can be done. I once had to dig through a pile of Exelixis kinase patents, looking for structures for their clinical candidates, and after about a week, I concluded that it just couldn't be done. And they're not alone.