222412-70-6Relevant articles and documents
Reversible Generation of Labile Secondary Carbocations from Alcohols in the Nanospace of H-Mordenite and Their Long-Lasting Preservation at Ambient Temperature
Masui, Yoichi,Hattori, Taiki,Onaka, Makoto
, p. 8612 - 8620 (2017/07/06)
Secondary carbocations are rarely observed spectrometrically for prolonged durations at ambient temperatures because of their instability. In this study, when 4,4′-difluorobenzhydrol (1) was mixed with H-mordenite (H-Mor), the 4,4′-difluorodiphenylmethyl cation (2) was generated as the main product, identified by UV-vis and 13C-MAS NMR spectroscopies, and was preserved for over 1 week at ambient temperature. Surprisingly, the polymerization and disproportionation of 1 barely proceeded within the micropores of H-Mor. However, these side reactions prevailed in TfOH and formation of 2 was not observed. Preservation of other secondary carbocations from benzhydrol, 4,4′-dichlorobenzhydrol, and 9-fluorenol was also realized in H-Mor. It was confirmed that the generation of 2 from 1 was controlled by thermodynamic equilibrium rather than kinetic regulations. The equilibrium between 2 and 1 was accompanied by reversible chromism, which could be easily controlled by altering the moisture content in H-Mor. Moreover, novel insights into specific acid catalysis in zeolites densely populated with acid sites on the inner surface of micropores are described herein.
Efficient synthesis of 2H & 13C labeled benzaldehydes via regio-selective formylation
Boga, Sobhana B.,Alhassan, Abdul B.,Hesk, David
, p. 4442 - 4444 (2014/08/05)
Benzaldehydes are important building blocks in synthetic organic chemistry that have wide applications for the synthesis of natural products and pharmaceutical drugs. Herein we report a general synthetic methodology for the synthesis of highly functionalized 2H and 13C labeled benzaldehydes in transfer of isotopic purity >99% via regio-selective formylation. Regio-selective deprotonation of substituted benzene 1 with LDA/n-BuLi at -78 °C and treatment with DMF-d7 or EtO- 13CHO led to the synthesis of 2-deutero-1,3-disubstituted benzaldehydes 2/4 in moderate to good yields. The synthetic methodology described represents a simple yet versatile route to functionalized formyl-deuterated, tritiated 13C and 14C labeled benzaldehydes.
Atorvastatin, an HMG-CoA reductase inhibitor and effective lipid-regulating agent. Part III. Syntheses of [2H5]-, [13C8], and [13C7,15N]atorvastatin and their application in metabolic and pharmacokinetic studies
Woo, Peter W. K.,Hartman, Jon,Hicks, James,Hayes, Roger
, p. 135 - 145 (2007/10/03)
Three stable-isotope-labeled forms of atorvastatin, [2H5], [13C8], and [13C7,15N], were synthesized. They were utilized primarily for metabolic mapping and pharmacokinetic studies of bioequivalence. Analytical assays were performed by using LC/MS/MS methodologies.
