207799-87-9Relevant academic research and scientific papers
β,β-Difluoro analogs of α-oxo-β-phenylpropionic acid and phenylalanine
Schlosser, Manfred,Brügger, Nadia,Schmidt, Werner,Amrhein, Nikolaus
, p. 7731 - 7742 (2007/10/03)
A simple three-step procedure converted the readily accessible (2-bromo-1,1-difluoroethyl)arenes (2) into α-aryl-α,α- difluoroacetaldehydes (1). Subsequent hydrocyanation, hydrolysis, oxidation and again hydrolysis afforded β-aryl-β,β-difluoro-α- oxopropionic acids (3). Reductive amination transformed the oxoacids 3 into a separable mixture of α-hydroxyacids 11 and racemic β,β-difluoro- β-phenylalanine derivatives (4). Enantiomerically pure β,β- difluorophenylalanine (L-4a) was obtained when α,α-difluoro-α- phenylacet-aldehyde (1a) was condensed with homochiral 1-phenylethylamine, hydrogen cyanide added to the resulting imine, the diastereomeric mixture thus produced hydrolyzed to the carboxamides (15) which were found to be separable by fractional crystallization or chromatography. The pKa values of the β-aryl-β,β-difluoroalanines (4) were measured and biological profile of the latter probed. 3-(4-Chlorophenyl)-3,3-difluoro-2-oxopropionic acid (4c) proved to be a potent (Ki 27 μM) and selective inhibitor of arogenate dehydratase, a key enzyme catalyzing the last step of the phenylalanine biosynthesis.
5[W(substituted aryl)alkenylene and alkynylene]-2,4-diaminopyrimidines as pesticides
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, (2008/06/13)
5-Substituted-2,4-diaminopyrimidines, and agriculturally acceptable salts thereof, when present in insecticidally or acaricidally effective amounts, and with a suitable agricultural carrier, are useful as active ingredients in novel insecticidal and acaricidal compositions. These pyrimidines may be represented by the following formula: STR1 wherein Ar is STR2 and wherein U is an alkenylene or alkynylene moiety, and R, R1, R2, R3, R4, V, W, X, Y, Z and n are as defined herein; also disclosed and claimed are novel intermediates thereof.
