Famotidine EP Impurity J, chemically defined as Methyl 3-[[[2-[(diaminomethylene)amino]thiazol-4-yl]methyl]sulfanyl]propanoate and commonly referred to as Famotidine Acid Methyl Ester, is an ester-type process impurity related to Famotidine, with molecular formula C₉H₁₄N₄O₂S₂ and molecular weight 274.36 g/mol. This impurity is typically formed during the Pinner-type conversion of the propanenitrile intermediate into the methyl imidate in methanol/HCl, where hydrolysis of the imidate gives the methyl ester instead of the amidine; it can also form by esterification of the corresponding propanoic acid (Impurity F) in methanolic media. It is therefore a key process-related marker for monitoring imidate formation, water control, and amidination efficiency during API manufacturing. Produced at Chemicea under tightly controlled synthetic and purification protocols, this reference standard supports impurity identification, method validation (AMV), and quality-control testing in accordance with EP monograph requirements for Famotidine, and finds routine application in ANDA and DMF regulatory submissions. Each batch is supplied with a comprehensive Certificate of Analysis supported by HPLC, ¹H-NMR, and Mass Spectrometry characterization data, ensuring dependable analytical traceability for regulatory and R&D laboratories worldwide. CAS No. 76824-14-1 | Explore complete technical documentation, Safety Data Sheet (SDS), and pricing.