Improved Synthetic Procedure of Zafirlukast

OBJECTIVE To improve the synthetic procedure of zafirlukast．METHODS Zafirlukast was synthesized from 5-nitro-1H-indole via methylation, alkylation, condensation, reduction and acylation. The methylation, alkylation and reduction are key steps in the procedure. RESULTS Zafirlukast was prepared in an overall yield of 31.6％.The structure of the target compound was confirmed by IR spectra, MS， H-NMR and elemental analysis．CONCLUSION The improved procedure avoids the use of expensive reagents and the target compound was synthesized in a convenient way. The method is suitable for industrial manufacture.