(Z)-N-(4-Ethyl-2-(ethylamino)thiazole-5-carbonyl)thiophene-2-carbimidoyl Cyanide-d5 is the isotope labelled analog of (Z)-N-(4-Ethyl-2-(ethylamino)thiazole-5-carbonyl)thiophene-2-carbimidoyl Cyanide (E917665); an impurity of Ethaboxam (E675700) which is a pesticide that is used as a fungicide against fungal infections in crops.