Methyl 5-(difluoromethyl)-4-nitro-3-(trifluoromethoxy)pyridine-2-carboxylate
Methyl 3-(difluoromethyl)-4-nitro-2-(trifluoromethoxy)pyridine-5-carboxylate
Ethyl 6-(difluoromethyl)-3-nitro-2-(trifluoromethoxy)pyridine-4-carboxylate
Methyl 3-(difluoromethyl)-2-nitro-5-(trifluoromethoxy)pyridine-6-carboxylate