Contents: PTC Tip of the Month, PT Catalyst of the Month, PTC Reaction of the Month, Challenge, Subscribe/Unsubscribe
of the Month - Recycling
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:
(click on links to request samples and quotes)
Please forward this PTC Tip of the Month to your colleagues and encourage them to subscribe
Top PTC Resources
for the PTC CD
Catalyst of the Month - Polyethylene
Glycol Dimethyl Ether
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.
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.
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.
& 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
To stop receiving the "PTC Tip of the Month," hit "Reply" and type "Remove" in the Subject line.
To receive the "PTC Tip of the Month," Contact Us and type "Subscribe to Tip" in the Comments.
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.
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.
Go to PTC Tip of the Month index