Example 1 of this patent is interesting because it compares the use of PTC with DMF for an N-alkylation using a potentially hydroxide-sensitive methyl bromo acetate and acetate product. In the DMF system, potassium carbonate was used as the base. It is possible that carbonate was used instead of NaOH to protect the esters from hydrolysis since NaOH might dissolve in DMF and hydrolyze the esters. In contrast, when using PTC, one can work with a water-immiscible solvent that keeps the NaOH separated from the organic soluble ester starting material and product.
The DMF system required a lot more workup unit operations, mostly extractions (as usual…due to water miscibility) and gave 66% yield after chromatography. The DMF system used 3 equiv of the methyl bromo acetate and also took 24 hours and 50 deg C. The PTC system achieved 94% yield using only 10 mole% excess of methyl bromo acetate, after 30 min at room temperature and workup required no extractions or chromatography to provide the product identical to that from the DMF process.
If your company can benefit from lower cost and higher performance alkylation reactions, now contact Marc Halpern to inquire about integrating the best PTC technology available provided by PTC Organics with your company’s technical and commercial goals.
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!).
