Deuteration and tritiation are important reactions to create compounds that are useful to determine reaction mechanisms and the fate of compounds.
Marc Halpern published many PTC deuterations from 1976 to 1983 for compounds with pKa’s from 16 (phenylacetonitrile) to 38 (thiophene) and many in between (such as fluorene pKa 23). The deuteration of diphenylmethane (pKa 33) was reported in Halpern’s Ph.D Thesis in 1983 in 97% isolated yield (100% dideuteration) at room temperature in 15 hrs using 18.3M NaOD in D2O and tetrabutylammonium hydrogen sulfate as the phase-transfer catalyst. This advantageous PTC procedure replaced the previous practice that used K t-butoxide as base, DMSO as solvent and methanol-d as the deuterium source.
The deuteration of a diphenylmethane derivative shown in the diagram also used tetrabutylammonium hydrogen sulfate as the phase-transfer catalyst. They used a lower concentration of 30% NaOD in D2O and achieved 95% dideuteration in the first deuteration reaction, then required a second deuteration pass to achieve 99% deuteration. In such PTC reactions, the base strength is very important to achieve the highest performance.
If your company wants to achieve the highest performance for strong base PTC reactions, now contact Marc Halpern of PTC Organics to explore a joint path forward.
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!).
