Guaifenesin is a [(R, S-3-92-methoxyphenoxy) propane-1,2-diol] is a classical drug extensively used as an expectorant in symptomatic management of coughs, associated with the ability to loosen and thin sputum and bronchial secretions and cease expectoration. It combined with bronchiodilators; decongestant, antihistamiics or opiate antitussives in numerous commercial liquids cough preparations. The objective of the present study is to synthesize the four impurities formed during the synthesis of guaifenesin, to establish the spectral properties of four impurities. It was observed that during the synthesis of guaifenesin many impurities were found. Apart from 1.5% of (2-mthoxyphenoxy)-1,3-propanediol (guaifenesin �-isomer), and 0.03% of guaicol, and other four impurities were detected by LC-MS data. These impurities were never synthesized and no structure elucidation was done to establish the LC-MS data. As an effort an attempt was made to synthesize these impurities and their structures were elucidated by spectral properties i.e., MASS,H NMR and IR.Thus,The purity profile of guaifenesin is successfully established.