Dec 19 (Reuters) - Syngenta says
* Syngenta and DuPont Crop Protection (DuPont) announced today the publication of a joint patent, focused on the development of a new herbicide chemistry class
* Collaboration on the project started in 2015 and has resulted in the joint patent entitled "Substituted cyclic amides and their use as herbicides."
* The new herbicide has entered into the pre-development stage and is expected to be launched in 2023. Further company coverage: (Reporting By Zurich newsroom)