Carvedilol is prepared by different synthetic approaches. One of the approach is the condensation of 4-(2, 3-epoxyprpoxy) carbazole with 2-(2-methoxyphenoxy) ethyl amine in monoglyme solvent. In this publication, impurities and their origin of formation during the synthesis of 4-(2, 3-epoxypropoxy) carbazole and 2-(2-methoxyphenoxy) ethyl amine is discussed. These impurities are synthesized and well characterized by spectral analysis.