Montelukast 1 is a famous drug demonstrated for the chronic and prophylaxis therapy of asthma. It behaves as a selective antagonist of the leukotriene D₄ receptor which causes the decrease of broncho constriction and eventuates in less inflammation. Montelukast is prescribed orally once daily which gives a profit in contrast with other drugs for pulmonary diseases such as asthma. The low stability and complex synthesis of Montelukast 1 present multitude difficulties for its large-scale production. Our present study demonstrates a novel and the industrially scalable process for the preparation of sodium (S,E)-2-(1-(((1-(3-(2-(7-chloroquinolin-2-yl)vinyl)phenyl)-3-(2-(methoxycarbonyl)phenyl)propyl)thio)methyl)cyclopropyl)acetate which is one of the key intermediates of the Montelukast sodium synthesis process. We demonstrated a novel process that resolves multitude prior limitations and problems. Our modified process (see in scheme 2), which details are shown in this paper, is appropriate for large-scale production of the active pharmaceutical ingredient (API) with many benefits generally known as Montelukast.