This patent is very worthwhile to study because it shows 21 sets of PTC epoxidation conditions with different quaternary ammonium cation phase-transfer catalysts, different counteranions to those quats, different phosphorous sources, different tungsten sources and different mole ratios. This PTC epoxidation has the added challenge of avoiding diepoxidation which is not trivial since PTC is so effective for epoxidation
For those of us with extensive experience in PTC epoxidations (including me), it is not surprising that the best results were obtained used methyl trioctylammonium hydrogen sulfate as the phase-transfer catalyst and phosphoric acid as the phosphorous source.
In particular, it is worthwhile to note that tetrabutylammonium hydrogen sulfate was ineffective. This phase-transfer catalyst is usually quite effective for most PTC applications, but PTC epoxidation is different. For those of you who are not familiar with PTC-hydrogen peroxide systems, quat hydrogen sulfates typically outperform quat chlorides when using phosphotungstate catalyst. PTC Organics has much experience with a variety of PTC-hydrogen peroxide-phosphotungstate systems for epoxidations and other types of oxidations.
If your company is performing commercial epoxidation or other types of commercial oxidations using hydrogen peroxide, now contact Marc Halpern of PTC Organics to explore a path to low-cost high performance green chemistry using phase-transfer catalysis for oxidations.
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!).
