A method of making a chemical product includes reacting a compound represented by Chemical Formula 1 with a metal alkyl chalcogenide using a palladium catalyst and a tertiary phosphine catalyst to obtain a first intermediate represented by Chemical Formula 2, obtaining a second intermediate represented by Chemical Formula 3 from the first intermediate, obtaining a third intermediate from the second intermediate and a compound represented by Chemical Formula 4, obtaining a fourth intermediate including a chalcogen-containing ring from the third intermediate, and performing a cyclization reaction of the fourth intermediate to obtain a fused heteroaromatic compound. A fused heteroaromatic compound obtained by the method, an intermediate thereof, and a synthetic method of the intermediate are disclosed.