Abstract

New herbicides are required to improve levels or spectrum of activity, to overcome resistance to existing products, or to replace older products under regulatory pressure. The first part of the talk will describe the discovery and optimization program for dioxopyritrione (Figure 1), a novel inhibitor of 4-hydroxyphenylpyruvate dioxygenase (HPPD) for use in wheat and barley. Once a development candidate is identified, a major issue is finding a safe, scalable, and cost-efficient synthesis. For the synthesis of herbicides, cost pressure is high and thus a major effort was required to reduce the cost of manufacturing. The second part of this talk will describe process research and development activities starting from the initial route scouting and ending with the scale-up in a pilot plant, including a large-scale photochemical step.