1332707-99-9Relevant academic research and scientific papers
Synthesis of 4-fluoro-β(4-fluorophenyl)-l-phenylalanine by an asymmetric phase-transfer catalyzed alkylation: Synthesis on scale and catalyst stability
Patterson, Daniel E.,Xie, Shiping,Jones, Lynda A.,Osterhout, Martin H.,Henry, Christopher G.,Roper, Thomas D.
, p. 624 - 627 (2007)
4-Fluoro-β-(4-fluorophenyl)-L-phenylalanine 1 was synthesized by the asymmetric phase-transfer catalyzed alkylation of tert-butyl glycinate-benzophenone Schiff base using the cinchona alkaloid derived catalyst 6. Upon scaling, it was observed that to achieve high levels of enantioselectivity, it was necessary to add the catalyst or base last. From these studies, insight into the stability of the catalyst 6 under the reaction conditions was gained.
An expedient, efficient and solvent-free synthesis of T3P-mediated amidation of benzhydrols with poorly reactive N-nucleophiles under MW irradiation
Cheruku, Srinivas,Manikyanally, Kumara N.,Mantelingu, Kempegowda,Nagarakere, Sandhya C.,Narayana, Yatheesh,Rangappa, Kanchugarakoppal S.,Sunilkumar, Makanahalli P.
, p. 4421 - 4426 (2022/03/14)
An expedient, efficient, economical, environmentally benign, and solvent free amidation protocol of benzhydrols with less reactive nitrogen nucleophiles assisted by propylphosphonic anhydride (T3P) under microwave irradiation has been developed. The methodology has been deployed for a wide range of heterocycles and electron-withdrawing & electron-donating groups. The protocol resulted in good to excellent yields under the given conditions (26 examples, 68-93% yield).
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
supporting information, 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.
Process development and optimization for production of a potassium ion channel blocker, ICA-17043
Mobele, Bingidimi I.,Venkatraman, Sripathy,McNaughton-Smith, Grant,Gibb, Cameron,Ulysse, Luckner G.,Lindmark, Carl A.,Shaw, Stephen,Marron, Brian,Spear, Kerry,Suto, Mark J.
, p. 1385 - 1392 (2012/11/07)
A scalable process for the manufacture of a potassium ion channel blocker was developed and optimized. Key features of the process include an optimized Grignard reaction, a direct cyanation of the intermediate trityl alcohol derivative, and an improved nitrile hydrolysis protocol, relative to the original acidic hydrolysis conditions, to generate the crude active pharmaceutical ingredient (API) with >95% HPLC purity. The Grignard and the cyanation reactions could be telescoped, resulting in an improved throughput compared to the original four-step process. An effective recrystallization of the API was also developed and the process scaled up to manufacture multiple batches at the pilot scale.
Sodium bisulfite: An efficient catalyst for ether formation via dehydration of aromatic/aliphatic alcohol
Wang, Hui,Zhu, Xingfei,Lu, Yangning,Li, Yue,Gao, Xiang
, p. 1180 - 1184 (2012/04/23)
Straightforward etherification of benzyl alcohols (1) via intermolecular dehydration can be efficiently catalyzed by sodium bisulfite under solvent-free conditions. In the presence of 0.3 mol% or 0.6 mol% amount of sodium bisulfite, symmetric and unsymmetric ethers are prepared from the corresponding alcohols in high yields (up to 95%). Etherification of benzhydryl alcohols is also discussed. Copyright
