Ethyl 6-chloro-2-(difluoromethyl)-3-fluoropyridine-4-carboxylate
Ethyl 6-chloro-2-(difluoromethyl)-4-fluoropyridine-3-carboxylate
Ethyl 2-chloro-6-(difluoromethyl)-3-fluoropyridine-5-carboxylate
Ethyl 2-chloro-5-(difluoromethyl)-6-fluoropyridine-3-carboxylate