Ethyl 5-cyano-2-(difluoromethyl)-3-(trifluoromethoxy)pyridine-4-acetate
Ethyl 4-cyano-5-(difluoromethyl)-3-(trifluoromethoxy)pyridine-2-acetate
Ethyl 4-cyano-2-(difluoromethyl)-3-(trifluoromethoxy)pyridine-5-acetate
Ethyl 5-cyano-3-(difluoromethyl)-4-(trifluoromethoxy)pyridine-2-acetate