Heptaldehyde, also known as 1-heptanal or n-heptanal, is a colorless to pale yellow, oily liquid with a fruity, oily odor. It's an aldehyde with a chain of seven carbon atoms. Heptaldehyde is practically insoluble in water but soluble in alcohol. It's mainly used in the fragrance and flavor industries as a precursor to components in perfumes and lubricants.