Ahab
Harmless
Posts: 3
Registered: 15-11-2009
Member Is Offline
Mood: No Mood
|
|
Synthesis from Patents?
Hi everyone,
Here's a n00b question... I was looking over patents the other day when i should've been in the lab doing real work. I came upon a few patents
detailing the use of Rh(I) and Ru(II) catalysts for one step conversion of an alkenol to the saturated ketone via Hydrogen shift to the enol, by
simply refluxing the alkenol in propanol in the presence of the catalyst under argon. In our lab we've been using a standard Pd/C hydrogenation
followed by Oppenauer oxidation to achieve the same results. I don't have the patent refs handy, i'll try and find them again when i'm on campus
tomorrow, but this seems like a much more efficient approach.
I don't have much experience with following protocols from patents and i was wondering how they 'detailed' they are with respect to the actual
requirements for success. i.e. is it safe to assume that if anhydrous alcohol is not explicitly stated, that absolute dryness isn't required? is there
any way to contact patent holders to get more information about their protocol?
Specifically, i'm wondering about the required dryness and purity of propanol, and what effect water would have on the reaction, if any... mostly
because I'm lazy and hate prepping anh. degassed solvents 
|
|
|
Arrhenius
Hazard to Others
Posts: 282
Registered: 17-8-2008
Location: US & A
Member Is Offline
Mood: Stochastic
|
|
This is a well known phenomenon of "alkene transposition" of allyl alcohols when you perform a hydrogenation under low pressure (or no H2). Brown's
catalyst and Wilkinson's catalyst (both Rhodium) are known to do this, as are palladium or platinum. It's not often use preparatively though. It
shouldn't need to be dry. Just use ethanol, isopropanol or ethyl acetate.
[Edited on 16-11-2009 by Arrhenius]
|
|
|
merrlin
Hazard to Others
Posts: 110
Registered: 3-4-2009
Member Is Offline
Mood: No Mood
|
|
The patent law (35 U.S.C. 112) requires that:
"The specification shall contain a written description of the invention, and of the manner and process of making and using it, in such full, clear,
concise, and exact terms as to enable any person skilled in the art to which it pertains, or with which it is most nearly connected, to make and use
the same, and shall set forth the best mode contemplated by the inventor of carrying out his invention."
Even though the statute does not use the term "undue experimentation," it has been interpreted (by the courts) to require that the claimed invention
be enabled so that any person skilled in the art can make and use the invention without undue experimentation. It has also been held that a patent
need not teach, and preferably omits, what is well known in the art.
An inventor's city of residence is usually listed on the patent, as is the assignee; if there is one. If the patent isn't too old, you can try
contacting the assignee or search a local phone directory.
The usefulness of a patent's specification can depend upon how one defines "skilled in the art" and "undue experimentation." The references cited in a
patent may also be instructive.
|
|
|
Vogelzang
Banned
Posts: 662
Registered: 26-4-2008
Member Is Offline
Mood: No Mood
|
|
Look at all of the references listed in each patent, including other patents, articles and books. Look up the classification of each patent and look
up the classes and subclasses in the manual of classification and then search the appropriate subclasses. The agents and/or attornies and/or
inventors wrote/write patents and the employees at the USPTO aren't allowed to write patents. The examiner can object to the specification and/or
suggest amendments to claims which he/she can make with the permission of the applicant.
They threw away all of the paper patents at the USPTO and now have them all on computer databases. You can see how fast the EAST database is in this
video. The camera that recorded this video is low resolution. The resolution on the EAST system is actually higher than 1024 X 768. I don't know
the exact resolution. The patent images are multi-page TIFF. Searching patents on the EAST system at the USPTO is at least a thousand times faster
than using the internet for searching patents (unless there's a secret internet II system working somewhere). They even have free WiFi in the public
search room and lobby.
http://www.4shared.com/account/file/112841042/b3a64204/EAST1...
They took this out for some reason:
http://www.4shared.com/account/file/39266902/4cd19191/Andrew...
There's various depository libraries around the country which have patent databases. I heard most have WEST and some have EAST. Some companies also
have their own databases.
[Edited on 16-11-2009 by Vogelzang]
|
|
|
not_important
International Hazard
Posts: 3873
Registered: 21-7-2006
Member Is Offline
Mood: No Mood
|
|
Note that several countries, India being one, allow for "trade secrets" in their patents, meaning important detail can be left out. Even with U.S.
patents the phrase "any person skilled in the art to which it pertains" has become a major loophole used to omit critical information.
|
|
|
Panache
International Hazard
Posts: 1290
Registered: 18-10-2007
Member Is Offline
Mood: Instead of being my deliverance, she had a resemblance to a Kat named Frankenstein
|
|
In my experience you have a fat chance in hell of getting a recent patent to work without significant experimentation. They are written to protect the
inventor should someone want to claim the invention but they rarely protect the inventor's actual rights of exclusive ownership.
This is because we live in a greedy capitalist world and everyone has figured out that for chemical processes it's neigh on impossible to litigate a
breach of ownership allegation, as such one is instructed by patent attorneys to write up your invention so that it would likely take you as much
effort getting it to work than if you had not ever read the patent.
Old patents are OK for chemical processes because they were written for the spirit of the thing.
i am cynical though this is because of my experience, if anyone every quotes patents to me as support for if something should work, i file them with
national enquirer articles.
Unfortunately this 'lying without lying' technique is infecting into the peer reviewed publications also.
|
|
|
Vogelzang
Banned
Posts: 662
Registered: 26-4-2008
Member Is Offline
Mood: No Mood
|
|
Did you look at any Soviet or Chinese patents?
|
|
|
ScienceSquirrel
International Hazard
Posts: 1863
Registered: 18-6-2008
Location: Brittany
Member Is Offline
Mood: Dogs are pets but cats are little furry humans with four feet and self determination! 
|
|
I have managed to reproduce patent described chemistry.
It depends on the patent and sometimes you have to read between the lines but it is not always down to a wish to hide the details but more down to
brevity in the experimental description.
Modern journal articles pack in more chemistry with more examples than say an article from the 1950's and this results in a loss of detail in my
opinion.
|
|
|
![[*]](images/xpblue/default_icon.gif){kind=icon}
