Karl-Otto Westphalen
Bosch
Network
Latest external collaboration on country level. Dive into details by clicking on the dots.
Publication
Featured researches published by Karl-Otto Westphalen.
Chimia | 2003
Peter Schäfer; Gerhard Hamprecht; Michael Puhl; Karl-Otto Westphalen; Cyrill Zagar
Novel phenylpyridines were synthesized based on molecular modeling oriented design by superposition of herbicidal phenyl-uracils, -indazoles, and diphenylethers. Their preparation follows Suzuki-type coupling conditions of reactive 2-chloro-pyridines with appropriate 2,5-substituted 4-chloro-phenyl boronic acids. Depending on the nature of substituents in the pyridine, and in particular the phenyl group, a large number of derivatives are readily accessible. Besides open-chain phenylpyridines also anellated compounds, such as pyridine-substituted 2H-1,4-benzothiazin-3(4H)-one or 3,4-dihydro-1H-quinolin-2-one, were prepared. Phenylpyridines act by inhibition of protoporphyrinogen-IX-oxidase. Their synthesis will be described in conjunction with structure-activity relationships. Phenylpyridines are highly active against many important broadleaf and grass weed species under pre- and - in particular - post-emergent conditions.
Pesticide Science | 1999
Gerhard Hamprecht; Horst Mayer; Karl-Otto Westphalen; Helmut Walter
New pyrimidine and triazine intermediates for herbicidal sulfonylureas are prepared as follows: 2,4-dichloro-6-methylpyrimidine is converted via a halogenation, halogen exchange and substitution sequence to 2-amino-4-trifluoromethyl-6-trifluoromethoxypyrimidine. New fluoromethyl-triazines are available starting from guanidine, trichloroacetonitrile and difluoroacetic anhydride, or alternatively from thiocarbamoyl guanidine and chlorodifluoroacetic ester ring closure. To obtain new o-fluoroalkyl-benzenesulfonamide precursors, o-chlorobenzaldehyde was fluorinated with sulfur tetrafluoride, or a bromobenzene derivative was subjected to a substitution reaction with sodium pentafluoropropionate. Sulfonylureas derived from trifluoromethylpyrimidines with an m-methylthio substituent are selective post-emergence herbicides in cotton, presumably due to sulfone metabolization. Selectivity in wheat is obtained by combining 4-methoxy-6-trifluoromethylpyrimidine with a lipophilic difluoromethyl-benzenesulfonamide moiety. Also in the difluoromethyl-triazine series, the combination with the difluoromethyl-benzenesulfonamide moiety is a good choice for wheat selectivity. Chlorodifluoromethyl- and trifluoromethyltriazines, however, combine better with an aromatic ester for best activity and selectivity in wheat. Selected compounds are undergoing broad field tests in wheat.
Archive | 2003
Bernd Sievernich; Max Landes; Elmar Kibler; Wolfgang Von Deyn; Helmut Walter; Martina Otten; Karl-Otto Westphalen; Herve Vantieghem
Archive | 1996
Deyn Wolfgang Von; Regina Luise Hill; Uwe Kardorff; Stefan Engel; Martina Otten; Marcus Vossen; Peter Plath; Harald Rang; Albrecht Harreus; Hartmann Konig; Helmut Walter; Karl-Otto Westphalen; Ulf Misslitz
Archive | 1999
Max Landes; Bernd Sievernich; Elmar Kibler; Wessel Nuyken; Helmut Walter; Karl-Otto Westphalen; Horst Mayer; Egon Haden; Christiaan Mulder; Alfons Schönhammer; Gerhard Hamprecht
Archive | 1998
Wolfgang Von Deyn; Regina Luise Hill; Uwe Kardorff; Ernst Baumann; Stefan Engel; Guido Mayer; Matthias Witschel; Michael Rack; Norbert Götz; Joachim Gebhardt; Ulf Miblitz; Helmut Walter; Karl-Otto Westphalen; Martina Otten; Joachim Rheinheimer
Archive | 1991
Matthias Wiesenfeldt; Karl-Heinz Etzbach; Peter Hofmeister; Christoph Kuenast; Karl-Otto Westphalen
Archive | 1991
Horst Mayer; Gerhard Hamprecht; Karl-Otto Westphalen; Helmut Walter; Matthias Gerber; Klaus Grossmann; Wilhelm Rademacher
Archive | 1997
Martina Otten; Norbert Götz; Wolfgang Von Deyn; Stefan Engel; Uwe Kardorff; Peter Plath; Regina Luise Hill; Matthias Witschel; Ulf Misslitz; Karl-Otto Westphalen; Helmut Walter
Archive | 1996
Wolfgang Von Deyn; Regina Luise Hill; Uwe Kardorff; Stefan Engel; Martina Otten; Marcus Vossen; Peter Plath; Harald Rang; Albrecht Harreus; Hartmann Konig; Helmut Walter; Karl-Otto Westphalen; Ulf Misslizt