Ethyl 2-amino-5-(difluoromethyl)-3-methylpyridine-4-carboxylate
Ethyl 2-amino-6-(difluoromethyl)-3-methylpyridine-5-carboxylate
Ethyl 6-amino-3-(difluoromethyl)-2-methylpyridine-4-carboxylate
Ethyl 6-amino-4-(difluoromethyl)-3-methylpyridine-2-carboxylate