783-61-9Relevant academic research and scientific papers
Efficient preparation of enantiomerically pure α-aryl-α- trifluoromethylglycines via Auto Seeded Programmed Polythermic Preferential Crystallization of 5-aryl-5-trifluoromethylhydantoins
Martin, Thibaut,Massif, Cedrik,Wermester, Nicolas,Linol, Julie,Tisse, Severine,Cardinael, Pascal,Coquerel, Gerard,Bouillon, Jean-Philippe
experimental part, p. 12 - 21 (2011/04/18)
Both pure enantiomers of α-phenyl- (or α-(p-methoxyphenyl))- α-trifluoromethyl-glycine and their corresponding methyl esters were obtained on a preparative scale using the following four-step sequence: the preparation of 5-aryl-5-trifluoromethylhydantoins by a Buecherer-Bergs reaction starting from trifluoromethyl aryl ketones, optical resolution by Auto Seeded Programmed Polythermic Preferential Crystallization (AS3PC), basic hydrolysis of the enantiopure hydantoins by means of aqueous barium hydroxide, and esterification of the amino acids with trimethylsilyldiazomethane. Hydantoins 5 and 6 were proven to crystallize as conglomerates using first second harmonic generation and then X-ray powder diffraction. The absolute stereochemistry of (+)-5-phenyl-5-trifluoromethylhydantoin 5b was established to be (S) by X-ray diffraction analysis on a single-crystal.
2-Trifluoromethyl-Substituted Amino Acids, 19. - 2-Trifluoromethyl α-Amino Acid Esters, Building Blocks for Trifluoromethyl-Substituted Ureas, Thioureas and Other Potential Biological Active Structures
Burger, Klaus,Schierlinger, Christian,Hollweck, Wolfgang,Muetze, Kerstin
, p. 399 - 406 (2007/10/02)
The preparative value of trifluoromethyl-substituted building blocks increases with the number of additional functionalities present. 2-Trifluoromethyl α-amino acid esters 2 represent readily available starting materials, excellently suited for the introd
