Contents:
PTC Tip of the Month, PTC Training PT Catalyst of the Month, PTC Reaction of the Month,
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9 metric tons of TBAC
A quantity of 9 MT of tetrabutyl ammonium
chloride is available from Nagase. Send your inquiry by E-mail
and use "TBAC 9MT" as the Subject Line.
PTC Tip
of the Month - CPhI
News: Dramatic Price Reduction for Hydrogen Sulfate Quats
Discussions with phase-transfer catalyst suppliers at CPhI last week revealed
that the price of hydrogen sulfate quats has dropped dramatically during the
past year as the volumes of these quats has now surpassed several hundred tons
per year. In fact, we heard of one price for tetrabutyl ammonium hydrogen
sulfate (TBAHS) in large quantities which rivals the price of the corresponding
bromide (TBAB) of 5 years ago. Since TBAHS almost always provides higher
reactivity than TBAB and also often reduces byproducts and environmental issues
related to bromide, we at PTC Organics intend to use TBAHS more often for
commercial development as a result of this drop in price. Commercial
suppliers of TBAHS are shown below in the PT Catalyst of the Month and we
recommend contacting them directly for quotes.
Please
forward this PTC Tip of the Month to your colleagues and encourage them
to
subscribe
Top PTC Resources |
PTC
Training
|
PTC
Training
The 2-day course "Practical
Phase-Transfer Catalysis" will be conducted in three locations in 2004.
Click here
for agenda. For registration, contact us by E-mail,
website, telephone (+1
856-222-1146) or fax (+1 856-222-1124).
February 2004 - Midland, Michigan
April 2004 - Tokyo, Japan
May 2004 - Mt. Laurel, New
Jersey (near PTC Organics)
Anytime - private
in-house course (optional Opportunity Identification Session under secrecy
agreement)
PT
Catalyst of the Month - Tetrabutyl
Ammonium Hydrogen Sulfate
Advantages
Initial reaction rates are often much higher than for the corresponding bromide
(TBAB) due to up to 1000 times less competition for extraction of the reacting
anion. The absence of halides allows users to sometimes claim the use of a
"greener" catalyst. Several reports of PTC oxidations using bleach or
hydrogen peroxide have noted that the hydrogen sulfate provides higher yield
than the corresponding bromide or chloride (note: highly detailed and diligent
safety analysis must be performed before attempting any PTC oxidation). Can
often be separated by
extraction into water. Price has dropped dramatically recently as volume
increased.
Disadvantages
Stability is limited at high temperatures in the presence of strong base due
primarily to Hofmann elimination. Price will probably always be higher than TBAB
though much lower than just a few years ago.
Reactivity
Parameters (Contact
PTC Organics for explanation)
Organophilicity
C# = 16; Accessibility q-value = 1.00. When using with base, make sure to take
into account the acidic proton of the HSO4 when determining how much base to
use.
Availability, Samples and Quotes from Competitors
Request samples and quotes from: Cognis
Corporation, Delta
Finochem, Dishman
Pharmaceuticals & Chemicals, GFS
Chemicals, Lion
Akzo, Nehachem,
Rutherford
Chemicals,
SACHEM
(click on link)
PTC Reaction of the Month - Selective
Etherification
This October 2003 patented reaction was performed in a 100
L reactor. A major challenge was successfully overcome by using PTC, which
was to avoid the formation of the difficult to remove N-alkylated contaminant,
which also represents a significant yield loss (previous yields were 50-74%!). Aki,
S.; Kurimura, M.; Nishi, T.; Minamikawa, J.; Tominaga, M.; Fukuyama, N.; Yamamoto, A. (Otsuka Pharmaceutical) US Patent 6,630,590
2003
Production Costs Too High?
Competitive Market?
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 and competitiveness.
INQUIRY: 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.
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
- Meet PTC Organics
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. For
details 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 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 #14 - November 2003
Copyright 2003 PTC Communications, Inc.
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