The phase-transfer catalysis community mourns the passing of Professor Sergei Yufit of Moscow on January 30, 2004 at the age of 78. Professor Yufit was a well-known scientist who worked nearly to his last days and was a very nice man.
Contents: PTC Tip of the Month, PTC Training PT Catalyst of the Month, PTC Reaction of the Month, Subscribe/Remove
comments for struggling organic chemical companies in this highly
Click and read these blunt comments from PTC Organics if your executives are losing sleep over competition from China/India.
Your company may be burning badly needed and easily recoverable profit!
of the Month - PTC
Retrofit Is Usually Capital-Free
Most phase-transfer catalysis processes in batch mode can be performed in standard reactors. Therefore, an advantage of retrofitting a non-PTC process with a much higher performance and lower cost PTC process is that the retrofit is very likely to be capital-free. Sometimes people think that special agitation systems may be needed to achieve intimate contact between two or more phases in PTC systems. However, that is rarely the case since the phase-transfer catalyst is supposed to do the work of bringing the reactants in contact and there should be very little dependence on interfacial processes (transfer of the quat-anion pair is very rapid and is a thermodynamically-controlled equilibrium process at relatively low agitation efficiency). In summary, worrying about capital investment for a PTC retrofit is usually not warranted, assuming you already have enough heat transfer capacity, agitation, a sight glass in the drain (for phase separation) and whatever else is required for your existing process.
Please forward this PTC Tip of the Month to your colleagues and encourage them to subscribe
Training - Save
$100 with early registration by March 1
The 2-day course "Practical Phase-Transfer Catalysis" will be conducted in the US in May 2004. Click here for agenda. Click here for registration or contact us by E-mail, website, telephone (+1 856-222-1146) or fax (+1 856-222-1124).
May 3-4, 2004 - Mt. Laurel, New Jersey (near PTC Organics) Early registration - save $100
May 2004 - Midland, Michigan
date to be announced - for details call +1 856-222-1146
Anytime - private in-house course (optional Opportunity Identification Session under secrecy agreement)
PTC Reaction of the Month - Epoxidation
of Terminal Alkene
The direct epoxidation of propylene is the holy grail for producing propylene oxide. An impressive yield of 94% PO (based on hydrogen peroxide) with a selectivity of 92% was achieved using [π-C5H5NC16H33][PW4O16] as the phase-transfer catalyst. The calculated throughput was only 4 g/L/hr. Much higher throughput for PTC epoxidation is possible and in fact, PTC Organics achieved a record space-time velocity for a proprietary PTC epoxidation of a different alkene of > 800 g/L/hr (!!!) in late 2003. The reference for the PTC PO reaction is: Gao, S.; Li, M., Lv, Y.; Zhou, N.; Xi, Z.; Org. Proc. Res. Dev., 2004, 131. By the way, "Organic Process Research and Development" is an excellent journal for process chemists and engineers and is naturally a good place to publish PTC articles (Trevor Laird of Scientific Update and Chris Schmid of Eli Lilly are the drivers of this journal).
Catalyst of the Month - Benzyl
Trimethyl Ammonium Chloride
This is the lowest cost quaternary ammonium salt (or nearly so depending on market conditions). High thermal stability in a variety of PTC applications, because it is not readily susceptible to one of the classic quat decomposition pathways, namely Hofmann elimination. Very high solubility and affinity for water, thereby facilitating separation from product by extraction into water when appropriate.
Often, but not always, "BTMAC" provides low phase-transfer catalytic activity. Stability can be an issue due to the tendency of BTMAC to benzylate nucleophiles. BTMAC is a contact poison.
Reactivity Parameters (Contact PTC Organics for explanation)
Organophilicity C# = 10; Accessibility q-value = approximately 3.25 (benzyl groups empirically behave like butyl groups from the standpoint of q-value)
Availability, Samples and Quotes from Competitors
Request samples and quotes from: Delta Finochem, Dishman Pharmaceuticals & Chemicals, Lion Akzo, SACHEM, Trigon (click on link)
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 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.
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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.
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 #17 - February 2004
Copyright 2004 PTC Communications, Inc.
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