The inventors claim that using phase-transfer catalysis for the reaction shown in the diagram leads to minimizing ring C-alkylation of the phenol and dialkylation. This is crucial since the inventors show that small amounts of the impurities lead to drastic alterations in biological activity.
The reaction appears to be a solid-liquid PTC system. In the 1970’s we found that when you starve a PTC system from water when there is an alkylation of an O-/C-ambident anion, you get more O-alkylation. This is consistent with similar results from the 1960’s that showed that as you minimize the presence of hydrogen bonding species in the alkylation of phenols and naphthols, you get more O-alkylation and less C-alkylation due to reduced selective solvation of the electronegative oxygen anion site.
We also find it interesting that the catalyst used is a classical head-and-tail surfactant, tetradecyl trimethyl ammonium bromide. The fact that other less polar PTC quats worked (including Aliquat 336) as well as PEG-400, means that the mechanism probably really is phase-transfer catalysis and probably not micellar.
If you or your company can benefit from achieving higher process performance in a shorter development time for this PTC reaction or any other reaction, by having access to the best PTC expertise available, NOW CONTACT Marc Halpern to inquire about using phase-transfer catalysis to achieve low-cost high-performance green chemistry. Remember, PTC excels in thousands of reactions in more than 30 reaction categories including strong base reactions, nucleophilic substitutions, oxidations and reductions
If you’re not sure if PTC can help your reaction, now fill out the PTC Project Evaluation Form and E-mail a scanned copy to Marc Halpern or send it by fax to Dr. Halpern at +1 856-222-1124. If your company does not have a secrecy agreement with PTC Organics Inc. already in place, please use “R-groups” instead of the exact chemical structures.
