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The Chemical Synthesis of Lipid A
Published in Helmut Brade, Steven M. Opal, Stefanie N. Vogel, David C. Morrison, Endotoxin in Health and Disease, 2020
Shoichi Kusumoto, Koichi Fukase, Masato Oikawa
An improved process of the same asymmetric hydrogenation of 3-keto acids, which employs a commercially available binap ruthenium catalyst at low pressure, was recently reported. A new method for the determination of the optical purity of the products was also presented in the same paper (17).
Synthesis and therapeutic delivery approaches for praziquantel: a patent review (2010-present)
Published in Expert Opinion on Therapeutic Patents, 2021
Tayo A. Adekiya, Pradeep Kumar, Pierre P.D. Kondiah, Viness Pillay, Yahya E. Choonara
Eberhardt et al. patented a method of preparing a pure R-praziquantel and analogues thereof using a stereoselective approach, which involves the asymmetric hydrogenation and the cyclization process in (WO2017036577A1) and (U.S. Patent 10,273,213) [31,32]. In other related invention by Maillard and coworkers in [33,34], methods of preparing R-praziquantel using a mixture of the enantiomers (R)-(I) and (S)-(I) of a Praziquanamine; an enatioenriched or enantiopure praziquantel precursor was patented in (ES2706314T3) and (U.S. Patent 9,932,337). Waechtler and coworkers [35,36] patented (WO2016078758A1) the preparation of enantiomerically and enantiopure enriched form of praziquantel from the recycling of (S)-praziquantel using the racemization technique, which is easy to scale-up, cost-effective, and reliable. The invention in (U.S. Patent. 20,140,370,555) and (U.S. Patent. 20,140,370,556) made use of readily available raw materials with low cost, environmentally friendly procedure and various conventionally and mature organic chemical reactions for large-scale production of a purified R-praziquantel using the high stereo selectivity, site selectivity, and region selectivity of an enzyme [37].