▎ 摘　　要

NOVELTY - 1-((E)-(7-(diethylamino)-2-oxo-chromen-3-yl)methyleneamino)-3-(2-hydroxypropyl)thiourea derivative (I) is new. USE - 1-((E)-(7-(diethylamino)-2-oxo-chromen-3-yl)methyleneamino)-3-(2-hydroxypropyl)thiourea derivative for detection in an aqueous system CN- (claimed). DETAILED DESCRIPTION - 1-((E)-(7-(diethylamino)-2-oxo-chromen-3-yl)methyleneamino)-3-(2-hydroxypropyl)thiourea derivative of formula (I) is new.. INDEPENDENT CLAIMS are included for the following: (1) a method for preparing 1-((E)-(7-(diethylamino)-2-oxo-chromen-3-yl)methyleneamino)-3-(2-hydroxypropyl)thiourea derivative (I); and (2) a method for recovering CN- detected by 1-((E)-(7-(diethylamino)-2-oxo-chromen-3-yl)methyleneamino)-3-(2-hydroxypropyl)thiourea derivative, which involves adding Cu2+ solution to the dispersion of 1-((E)-(7-(diethylamino)-2-oxo-chromen-3-yl)methyleneamino)-3-(2-hydroxypropyl)thiourea derivative after CN- detection, stirring and mixing, filtering, washing solid phase with deionized water, drying to obtain final product.