PTC Tip
of the Month - Crucial
Practical Difference Between "Phase-Transfer Catalyst" and "Cationic Surfactant"
A common misperception is that a quaternary ammonium "phase-transfer
catalyst" and "cationic surfactant" are the same thing. After
all, "isn't a quat, a quat"? It is true that most cationic
surfactants are quaternary ammonium salts and many phase-transfer catalysts also
also quaternary ammonium salts. However, there is an extremely important
distinction which we use in the design of practical applications (and sometimes
for patent purposes). If one uses a typical cationic surfactant such as cetyl
trimethyl ammonium bromide to enhance a reactant rate, emulsions are often
formed which can sometimes make workup and isolation of product so difficult as
to be impractical. In contrast, a good
phase-transfer catalyst will not only enhance the reaction rate, but a well
chosen phase-transfer catalyst will allow for phase separation within a minute
or so after stopping agitation. Good phase separation allows easy
product isolation and separation between product and waste. This is a major
practical advantage which can be the difference between a feasible and
non-feasible PTC application on any scale in the lab or plant. If you
would like to discuss which structures are more likely to create emulsions and
which structures are more likely to provide good catalyst separation, please
contact Marc Halpern at tel +1 856-222-1146 or by E-mail.
Please forward this PTC Tip of the Month to your colleagues and encourage them to subscribe
PTC
Consulting - Stop Wasting
Precious R&D Resources & Improve Performance
What if you could achieve PTC breakthrough processes in your lab in weeks
instead of months (if at all)? PTC Organics'
dedicated industrial phase-transfer catalysis experts have provided highly
specialized PTC consulting and other PTC services at 189 sites in the US, Europe
and Japan and have helped companies save > $150 million and improve overall R&D
effectiveness.
To improve route selection, process improvement, process development and
overall reaction performance, contact
Marc Halpern at tel +1 856-222-1146 or by E-mail.
PTC
Training - Plan
your training budget - November
2004 and May 2005 in Chicago and Newark
The course "Practical
Phase-Transfer Catalysis" will be conducted in Chicago and Newark later in
2004 and 2005. You will have the option of attending both days of the course or
choose only the "PTC Reactions" portion (e.g., for synthesis chemists)
or the "PTC Process Development" portion (for process
chemists/engineers). Starting in September, you will be able to purchase just
the manual (without taking the course) or the manual with a transcript of the
course. "Practical Phase-Transfer Catalysis" can also be conducted at your company anytime (North
America, Europe or Japan) as a private
in-house course. More than 530 chemists, engineers and managers at nearly
100 companies have participated in this highly rated course since 1996. Click here
for details and agenda
or contact us by E-mail or telephone (+1
856-222-1146) or fax (+1 856-222-1124).
Inexpensive patent attorney (United States) familiar with Phase-Transfer Catalysis, organic chemistry and biochemistry. Contact Mannie Morgenstern by E-mail or at telephone 818-788-5531 (California).
PTC
Reaction of the Month - Oxidation
of Sulfide to Sulfone
Chemists as Sumika Fine Chemicals performed a mild high yield oxidation of a
thioether to the sulfone using hydrogen peroxide and catalyzed by 1 mole% each
of TBAB, phenyl phosphonic acid and sodium tungstate. Shintaku, T.; Katsura, T.; Itaya, N. (Sumika Fine Chemicals) US Patent 6,740,770
25-May-2004
PT
Catalyst of the Month - Tetraethylene
Glycol Dimethyl Ether "Tetraglyme"
Advantages
When glymes work in PTC reactions, they are low cost alternative to using crown
ethers; an excellent brochure comparing glymes to quats for a variety of PTC
reactions is available from Clariant.
Disadvantages
Glymes do not always work for PTC reactions; specific guidelines do not yet
exist for choosing glymes as phase-transfer catalysts, so
"trial-and-error" is the recommended method for screening
Availability, Samples and Quotes from Competitors
Request samples and quotes from: Clariant
(click on link) - contact Dan Patterson
(US)
Other
Phase-Transfer Catalysts:
PTC
Supplier Directory: choose
from a dozen suppliers & 80 PT catalysts and ask for free samples &
quotes.
PTC
Technology for Licensing
For details, contact Marc Halpern at tel
+1 856-222-1146 or by E-mail.
Pharma
-
for PTC options during route selection, contact Marc Halpern by E-mail,
website or telephone (+1
856-222-1146).
Subscribe/Remove
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contact us by E-mail at tip@phasetransfer.com
or by telephone at +1 856-222-1146.
To receive the "PTC Tip of the Month," contact us at www.ptcorganics.com/ContactUs.htm
and note "Subscribe to Tip" in the Comments or by telephone at +1
856-222-1146.
Before
performing any PTC reactions read this important message
Organic chemical reactions are inherently dangerous. Moreover, phase-transfer
catalysis may provide rate and other enhancements which can intensify associated
hazards. Under no circumstances should anyone perform any procedure on any scale
based in whole or in part on any of the contents of this information provided
here before
thoroughly establishing safe operating procedures and performing a full and
competent hazardous operations analysis with the participation of qualified
technical personal trained in chemical, engineering, safety, industrial hygiene
and environmental disciplines and sciences.
Policy
The list of PTC Tip of the Month subscribers
will not be sold, rented or transferred and will be used only by PTC
Communications, Inc. and PTC Organics, Inc. to provide information related to
Phase-Transfer Catalysis. PTC Communications, Inc. reserves the right to
distribute the PTC Tip of the Month to selected industrial chemists, engineers and
managers.
PTC Tip of the Month #21 - June 2004
Copyright 2004 PTC Communications, Inc.
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