This patent demonstrates, among other things, the advantageous practice of performing two consecutive PTC reactions and carrying forward the intermediate from the first PTC reaction in the crude organic phase directly into the PTC second reaction without isolating the intermediate. The most interesting part of this patent is the second step which is a PTC esterification-hydrolysis of a benzal chloride to an aldehyde.
The first reaction was a standard PTC etherification of a phenol. The second reaction starts with a modification of a common method for using PTC to hydrolyze an alkyl halide to an alcohol which is to esterify the alkyl halide using an acetate or formate (sodium acetate in this case). PTC excels in such esterifications of carboxylates with alky halides. Since the substrate in this patent is a substituted benzal chloride (two chlorine atoms), the transient product is a geminal diol that collapses into the aldehyde by dehydration.
The PTC esterification-hydrolysis of the benzal chloride to the aldehyde uses the TBAB from the first reaction that remains in the organic phase and the inventors add a bit more TBAB for the second reaction.
If your company wants to achieve lower-cost higher-performance green chemistry processes contact Dr. Marc Halpern of PTC Organics to explore integrating unmatched highly specialized expertise in industrial PTC with your commercial goals and improve R&D efficiency at the same time.
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!).
