Dwane H. Campbell

Bio: Dwane H. Campbell is an academic researcher from Monsanto. The author has contributed to research in topics: Carbon-13 NMR & Trifluoromethyl. The author has an hindex of 2, co-authored 4 publications receiving 53 citations.

Ammonium glyphosate compositions and process for their preparation

Abstract: A process is provided for preparing a downstream processable ammonium glyphosate paste. The process includes mixing in a reactor (i) particulate glyphosate acid, (ii) ammonia, (iii) adjuvant, and (iii) water. The reaction of glyphosate acid with ammonia causes the generation of heat resulting in the partial evaporation of the water such that an ammonium glyphosate paste is formed, having a moisture content of about 2 % to about 20 % by weight. The addition of the adjuvant to the reactor (i) increases the rate at which the glyphosate acid and ammonia react to form ammonium glyphosate and/or (ii) reduces the flow resistance of the reaction mass as it is being conveyed to the product discharge region of the reactor. The ammonium glyphosate paste may then be further processed to form a granular herbicidal composition.

Synthesis and 13C NMR of (Trifluoromethyl)hydroxypyrazoles.

Abstract: Reaction of ethyl 4,4,4-trifluoroacetoacetate with methylhydrazine produced not only the previously reported 5-hydroxy-3-(trifluoromethyl)pyrazole 1 but also its unknown isomer the 3-hydroxy-5-(trifluoromethyl)pyrazole 4. The structure assignements are etablished based on 13 C NMR spectra. Compound 1 was converted to 5-chloro-3-(trifluoromethyl)pyrazolecarboxylic acid 3 in two steps.

Synthesis and Biological Activities of Novel Pyrazole Oxime Derivatives Containing a 2-Chloro-5-thiazolyl Moiety

Abstract: A series of novel pyrazole oxime derivatives containing a 2-chloro-5-thiazolyl moiety were synthesized. Their structures were confirmed by (1)H NMR, (13)C NMR, and elemental analysis. The preliminary bioassays showed that all of the title compounds had low acaricidal activity against Tetranychus cinnabarinus . However, most of them exhibited excellent insecticidal activity against Aphis medicagini at the dosage of 0.5 mg/mL, and some compounds still showed good insecticidal activity against A. medicagini even at the dosage of 0.2 mg/mL. Meanwhile, some title compounds displayed fungicidal and plant growth regulatory activities.

Synthesis and Antitumor Activity of 5-Trifluoromethyl-2,4- dihydropyrazol-3-one Nucleosides

Abstract: 2,4-Dihydropyrazole glucosides 3a-3c were prepared and tested for theirantitumor activity. The structures of these compounds were established by 1H and 13C-NMR spectroscopy. Glucoside 3b shows an in vitro IC50 value of 16.4 μM againstproliferation of the human promyelotic leukemia (HL60) cell line.