US 12,134,618 B2
Method of preparation of florasulam
Jossian Oppenheimer, Midland, MI (US); Michael Gullo, Midland, MI (US); David E. Podhorez, Midland, MI (US); and Justin A. Alberts, Midland, MI (US)
Assigned to Corteva Agriscience LLC, , IN (US)
Appl. No. 16/754,856
Filed by Dow AgroSciences LLC, Indianapolis, IN (US)
PCT Filed Oct. 10, 2018, PCT No. PCT/US2018/055115
§ 371(c)(1), (2) Date Apr. 9, 2020,
PCT Pub. No. WO2019/074995, PCT Pub. Date Apr. 18, 2019.
Claims priority of provisional application 62/570,271, filed on Oct. 10, 2017.
Prior Publication US 2021/0198262 A1, Jul. 1, 2021
Int. Cl. A01N 43/90 (2006.01); C07D 487/04 (2006.01)
CPC C07D 487/04 (2013.01) [A01N 43/90 (2013.01)] 18 Claims
 
1. A method of preparing florasulam (compound I)

OG Complex Work Unit Chemistry
comprising:
a) controlled adding of sulfonyl chloride III

OG Complex Work Unit Chemistry
to 2,6-difluoroaniline over a period of at least 1 hour while maintaining a temperature during the adding of 15° C. to 35° C. to form a mixture; and
b) controlled adding of a base to the mixture formed in step a) over a period of at least 0.5 hours while maintaining a temperature during the adding of 15° C. to 30° C.