A Telescopic, Scalable and Industrially Feasible Method for the Synthesis of Antidepressant Drug, Moclobemide

An improved, scalable, industrially feasible telescopic process for multigram synthesis of highly commercialized antidepressant drug, moclobemide has been developed. Unlike the conventional approaches, this process enjoys the privilege of being an economical, operationally simple, effectively scalable, and quantitative method for the synthesis of amide-containing drug moclobemide, showcasing easy isolation and purification without the aid of column chromatography. An environmentally benign reagent combination of TBN and NHS very effectively converts the acyl source, 4-chlorobenzaldehyde into its N-hydroxysuccinimide ester intermediate, which simply affords the drug molecule after nucleophilic substitution with the amine source. The synthetic process has successfully been scaled-up upto ~145 g scale with 75 % overall yield and >95 % first crop HPLC purity.