Bayer Agrochem

Nithiazine was the lead compound in syntheses of the first commercially successful neonicotinoids that surpassed the parent compound in both insecticidal properties and environmental stability. A 6-chloro-3-methylpyridine moiety and a pharmacophore of varying structures (Figure 2) are the two components of a neonicotinoid molecule. Insecticides of the first generation of neonicotinoids are best represented by imidacloprid (Nihon Bayer Agrochem, Japan) (Figure 2) and are also called chloronicotinyls or chloropyridyls. 

The first syntheses were developed in the 1980s by Kozo Shiokawa at Nihon Bayer Agrochem. The iminoimidazolidine was formed by reaction of the diamine with cyanogen bromide however, this product could be nitrated on the nitrogen in only poor yields (a). [ 145] Shigeru Kojima prepared imidacloprid by reaction of the diamine with dimethyl nitrocarboimidodithioate in dichloro-methane (b). [146] The best synthesis is probably the reaction of 2-chloro-5-(chloromethyl)pyridine and 2-nitroiminoimidazolidine with potassium carbonate in acetonitrile. [ 147] The reaction may be catalysed by 3-5 mole percent of caesium chloride (c). [148]... 

T. Goto, H. Hayakawa, Y. Watanabe, S. Narabu, A. Yanagi (Nihon Bayer Agrochem), EP 578090 1994 Chem. Abstr. 121 57514. 

Whereas the United States are the biggest agrochemicals market, the top three companies, Bayer CropScience, Syngenta, and BASF Agricultural Products Nutrition, are located in Germany and Switzerland (see Table 11.6). The United States follows in importance. Out of the top—albeit mainly small ones—20 companies, 8 companies are based in Japan. 

Bayer AG, Agrochemical Division, Research Biochemistry, Plant Protection Center Monheim, D5090 Leverkusen, Federal Republic of Germany... 

As chairman of the Division of Pesticide Chemistry it is my special pleasure and privilege to introduce this year s recipient of the Burdick and Jackson International Award in Pesticide Chemistry. This award is given annually for "outstanding contributions to research in pesticide chemistry" and represents one of the highest honors that the agrochemicals community can bestow on one of its members. We are here today to present this honor to our distinguished colleague, Prof. Karl Heinz Btichel, Director of Central Research with Bayer AG. 

In my first years with the Bayer Research and Development organization, I particularly enjoyed support from Prof. Wegler, then Director of Research, and Dr. RIsse, then Head of the Agrochemicals Division. Both gentlemen gave me not only the freedom, but also a budget to follow my ideas in a sometimes individual way. 

I accept this ACS Award as a recognition of the 90-year tradition of agrochemical research of the Bayer Company and the many pioneering achievements of this organization for the benefit of agriculture. 

The A/-phenylpyrazole insecticide fipronil, already discussed in Section 2.1.1.2, contains the unusual trifluoromethylsulfinyl substituent, not often seen in agrochemical chemistry. Following the introduction of fipronil, several chemistries related to fipronil were launched, including acetoprole [105], an insecticide with acaricidal and nematicidal activity, and ethiprole [106], a systemic insecticide for the control of a broad spectrum of insects, both from Bayer CropScience. 

Among the contrarians, Bayer has had for historical reasons a different approach to the problem of remaining a well-rounded producer of chemicals. It has always been a leader in such specialty chemicals as plastics and rubber additives and supplies master batches through its subsidiary Rhein Chemie. Its polymers are mainly centered on synthetic elastomers and specialty plastics like polyurethanes and polycarbonates that Bayer itself develops. These are not subjected to the cutthroat competition that commodity thermoplastics are. Bayer has remained involved in aroma chemicals with a well-known subsidiary, Haarmann Reimer. In pharmaceuticals the company occupies an honorable rank, although in the future its management may want to separate that branch from the rest of its activities in preparation for further alliances. Like BASF, Bayer considers its agrochemical line as a core business. However, unlike BASF, it is less interested in integrating upstream production to oil raw... 

Our thanks are due to ICI Agrochemicals, Ciba-Geigy Agrochemicals, Bayer AG and the UK Home-Grown Cereals Authority, for financial support for our research on fungicide resistance, which has provided much of the background for this contribution. 

W. Draber, B. PitteP, and A. TrebsP Agrochemical Research Monheim, Bayer AG, 5090 Leverkusen, Federal... 

Flurtamone was introduced by Chevron Chemical Co. and later acquired by Rhone-Poulenc Agrochemical (now Bayer CropScience). It is incorporated preplant, pre-emergence or applied post-emergence for the control of broadleaved and some grass weeds in small grains, peanuts, cotton, peas and sunflowers at 250-375 g ha . The main metabolite is trifluoromethylbenzoic add and, 10 months after application, no residues could be detected. Field DT50 46-65 days. 

We cannot maintain our present high density of population in the developed world, nor deal with malnutrition in the developing world unless we preserve our food supply from attacks by insects and fungi and from competition by weeds. The world market for agrochemicals produced by multinationals such as Bayer CropScience and Syngenta is over 10bn per annum divided between herbicides, fungicides, and insecticides. 

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