A method for preparing montelukast and Intermediates used in the same

摘要

Claim 1: a method to repair montelukast or its sodium salt of formula (1) comprises the following steps: (a) allowing a compound of the formula (5) halophosphate diol reacts with the compound of the formula (4) in a Solvent in the presence of a base to produce a compound FOS Fato of formula (3) and (b) coupling the phosphate Compound of formula (3) with an acid compound.Acid of formula (2) in a Solvent in the presence of a base, wherein, R is H or na; r1 is H, Methyl or Ethyl; R2 is Methyl, Ethyl, or phenyl, and X is Halogen, Sulfur or Oxygen is.Claim 1: a phosphate Compound of formula (3), which is used as an intermediate to produce montelukast or its sodium salt, according to claim 1: where, R2 is Methyl, Ethyl, or phenyl; and sulfur or Oxygen.