Contents: PTC Tip of the Month, PT Catalyst of the Month, PTC Reaction of the Month, Challenge, Subscribe/Unsubscribe
PTC Tip
of the Month - Recycling
TBAB
TBAB is recovered and recycled in actual commercial PTC processes which are cost
sensitive. Recovery and recycle of TBAB is based on the concept that TBAB can be
extracted away from the product into water and can be salted out as a "wet
TBAB" phase by adjusting the ionic strength of the aqueous wash using NaCl
or NaOH. For example, TBAB has been reported to be soluble to the extent of only
0.07% in 15% NaOH. However, it should be remembered that the volume and number
of water washes to effectively remove TBAB from the product depends on the
solvent and other factors and may be significant. In these cases, it may be
better to consider more water-soluble phase-transfer catalysts. Commercial
suppliers of TBAB in the US, Europe, India and Japan include:
Cognis,
Delta Finochem,
Dishman,
GFS,
Lion Akzo,
Nehachem,
Rutherford,
SACHEM,
Trigon
(click on links to
request samples and quotes)
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Challenge
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PT
Catalyst of the Month - Polyethylene
Glycol Dimethyl Ether
Advantages
High thermal stability even in the presence of strong base, low toxicity, low
cost, sometimes works at levels of a few mole%, can often be separated by
extraction into water.
Disadvantages
Doesn't always work in low catalytic quantities, no clear guidelines for
choice...use trial and error, may cause emulsions in certain cases.
Availability, Samples and Quotes from Competitors
Request samples and quotes from: Clariant
and Ferro
(click on link)
PTC Reaction of the Month - Nucleophilic
Aromatic Etherification Challenge
The nucleophilic aromatic etherification shown below is important in the
manufacture of a key dye intermediate. This reaction and its process parameters
were examined thoroughly by Yadav, G.; Naik, S.; Org. Proc. Res. Dev.; 1999,
3, 83. The reaction was performed under solid-liquid PTC conditions using
solid sodium methoxide (methylate) and agitation was not an issue above a
certain rpm, as would be expected from an I-reaction (consistent with the
reported energy of activation of 14.4 kcal/mole). The authors
achieved 100% conversion in 45 min at "ambient" temperature with only
< 0.5 mole% TBAB which is quite good. However, if one were concerned
about the cost of manufacture, there are a few factors which might be changed.
Any ideas? E-mail your supported
answer to us by 15-Nov-2003, from a valid industrial
company E-mail address, and PTC Organics will send the
CD-ROM "The Best of
Industrial PTC" to the top five answers, as judged by PTC Organics.
An answer will be provided by PTC Organics in the December 2003 PTC Tip of the
Month.
Challenge -
Production Costs Too High?
Increase Yield: Could
a 5-10% yield increase significantly increase profit (e.g., is your current
yield < 88%)?
Reduce Cycle Time:
Does your current process take > 8 hours?
Want to eliminate isolation of intermediates?
Replace Strong Base
with NaOH: Are you using alkoxides
(e.g., methylate, t-butoxide), Na hydride, Na amide?
Improve Selectivity:
Do you need to improve product assay or
simplify workup? Too much hydrolysis?
Reduce Excess Reactants:
Are you using > 10% excess of any
expensive and/or hazardous reactant?
Replace Solvent for
Easier Workup: Are you using DMSO,
NMP, DMF, DMAC or undesirable solvent?
Increase Reactor
Volume Efficiency: Does solvent
and/or water take up > 50% of your reactor volume?
Other Challenges:
Competing with China and India? Too much waste?
Working with water-sensitive
compounds?
If you answered "Yes" to even one question above and your
reaction type is one of 35 on the
PTC Reaction
list, then Phase-Transfer Catalysis may help you achieve BREAKTHROUGH process
improvement and improve profit margin (competing with China & India?).
INQUIRY & GIFT
OF APPRECIATION: Contact Marc
Halpern at PTC Organics by E-mail,
website, telephone (+1
856-222-1146) or fax (+1 856-222-1124) to inquire about using PTC to improve
process performance. If your inquiry is for an active commercial process at your
industrial
company in North America, Europe or Japan then we will send you a GIFT
OF APPRECIATION, the CD-ROM
"The Best of Industrial Phase-Transfer Catalysis" (offer valid while quantities
last; 100 as of August 2003). PTC Organics reserves the right to
distribute "The Best of Industrial Phase-Transfer Catalysis" to selected industrial chemists, engineers and
managers. DO NOT DISCLOSE PROPRIETARY SPECIFIC REACTION INFORMATION WITHOUT A
SECRECY AGREEMENT.
As the world leader in industrial
phase-transfer catalysis, PTC Organics offers PTC
Breakthrough Process Screening for rapid and highly effective evaluation of
breakthrough high-performance low-cost phase-transfer catalysis processes.
Conferences
& PTC Training - Meet PTC Organics
CPhI - October 27-29, 2003 in
Frankfurt, Germany
Informex 2004 - January
19-22, 2004 in Las Vegas, Nevada, USA. PTC Organics booth # will be 2206.
2-Day PTC Course - public PTC courses are being planned for Michigan, New Jersey
& Japan for the 1st half of 2004. Read upcoming PTC Tips of the Month for
details or Contact
Us
PTC Organics is a member of SOCMA
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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 E-mail 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 #13 - October 2003
Copyright 2003 PTC Communications, Inc.
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