Abstract

Synthesis of pranlukast

Author(s): Yue Zhang, Hai-wen Song, Yi-feng Yu, Ting-ting liu, Shi-xia Xu, Man Du, Yongguo Wang

4-(4-Phenylbutoxy)benzoic acid (2), which was prepared from tetrahydrofuran (4) by ring-opening, Friedel-Crafts alkylation, bromination and etherification, reacted with 3-amino-2-hydroxyacetophenone (3) to give 3-[4-(4-phenylbutoxy)benzoic amide]-2- hydroxyacetophenone (11), followed by reacting in the presence of 1H-tetrazol-5-ethyl formate (12) and cyclization to give pranlukast (1)with the overall yield of 24.7%(based on 4).