2-Cyanopyrimidine is a key intermediate in the synthesis of bosentan. Bosentan is a kind of drug for the treatment of pulmonary hypertension, which is suitable for the treatment of patients with pulmonary hypertension (PAH) of who functional classification II-IV (who group 1), in order to improve the exercise ability of patients and reduce clinical deterioration. Studies supporting the effectiveness of this product mainly included patients with idiopathic or hereditary PAH (60%) of who functional classification II-IV, PAH associated with connective tissue disease (21%) and PAH associated with left to right shunt congenital heart disease (18%).