From time to time, we report on the use of tetrabutylammonium bromide to catalyze the reaction of epoxides with carbon dioxide to form cyclic carbonates. The reaction shown in the diagram is another such application.
The mechanism for this reaction is shown in an earlier PTC Tip of the Month here:
http://phasetransfercatalysis.com/ptc_reaction/ptc-carboxylation-using-co2/.
Interestingly, the reaction was done at atmospheric pressure and bubbling carbon dioxide. Such reactions are typically performed under pressure as per the following examples:
http://phasetransfercatalysis.com/ptc_reaction/cyclic-carbonates-from-carbon-dioxide-and-epoxides/
http://phasetransfercatalysis.com/ptc_tip/tbab-catalyzed-cyclic-carbonate-from-epoxidized-soybean-oil-and-carbon-dioxide/
http://phasetransfercatalysis.com/ptc_catalyst/tbab-cobalt-acetate-triphenylphosphine/
The starting material for this reaction, bisphenol A diglycidyl ether (DGEBA is the abbreviation used in the publication), is also made using phase-transfer catalysis. US Patent 4,276,406 describes a version of the historical Dow Chemical process that reacts bisphenol A with epichlorohydrin using benzyl trimethyl ammonium chloride to produce DGEBA for commodity scale epoxy resins.
On top of that yet another PTC reaction is used to build the molecular weight of epoxy resins from DGEBA. The phase-transfer catalyst used to build epoxy resin molecular weight is usually an alkyl triphenyl phosphonium salt.
About Marc Halpern
Dr. Halpern is founder and president of PTC Organics, Inc., the only company dedicated exclusively to developing low-cost high-performance green chemistry processes for the manufacture of organic chemicals using Phase Transfer Catalysis. Dr. Halpern has innovated PTC breakthroughs for pharmaceuticals, agrochemicals, petrochemicals, monomers, polymers, flavors & fragrances, dyes & pigments and solvents. Dr. Halpern has provided PTC services on-site at more than 260 industrial process R&D departments in 37 countries and has helped chemical companies save > $200 million. Dr. Halpern co-authored five books including the best-selling “Phase-Transfer Catalysis: Fundamentals, Applications and Industrial Perspectives” and has presented the 2-day course “Practical Phase-Transfer Catalysis” at 50 locations in the US, Europe and Asia.
Dr. Halpern founded the journal “Industrial Phase-Transfer Catalysis” and “The PTC Tip of the Month” enjoyed by 2,100 qualified subscribers, now beyond 130 issues. In 2014, Dr. Halpern is celebrating his 30th year in the chemical industry, including serving as a process chemist at Dow Chemical, a supervisor of process chemistry at ICI, Director of R&D at Sybron Chemicals and founder and president of PTC Organics Inc. (15 years) and PTC Communications Inc. (20 years). Dr. Halpern also co-founded PTC Interface Inc. in 1989 and PTC Value Recovery Inc. in 1999. His academic breakthroughs include the PTC pKa Guidelines, the q-value for quat accessibility and he has achieved industrial PTC breakthroughs for a dozen strong base reactions as well as esterifications, transesterifications, epoxidations and chloromethylations plus contributed to more than 100 other industrial PTC process development projects.
Dr. Halpern has dedicated his adult life to his family and to phase-transfer catalysis (in that order!).
