Diclofenac Ethyl Ester, chemically known as Ethyl [2-[(2,6-dichlorophenyl)amino]phenyl]acetate and pharmacopoeially designated Aceclofenac EP Impurity C, is the ethyl ester of Diclofenac, with molecular formula C₁₆H₁₅Cl₂NO₂ and molecular weight 324.20 g/mol. Structurally, this compound forms by esterification of the Diclofenac acetic acid side chain with ethanol, for example when ethanol is used as a reaction or crystallization solvent. It serves a dual analytical role: as a process-related impurity marker in Diclofenac manufacturing and as a specified impurity in Aceclofenac, where Diclofenac is the starting material and related esters can be carried into the final API. Manufactured at Chemicea under precisely controlled esterification and purification protocols, this reference standard supports impurity identification, method validation (AMV), and quality-control testing in accordance with the EP and BP monograph requirements for Aceclofenac and with ICH Q3A requirements for Diclofenac, and is routinely used 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 pharmaceutical R&D and QC laboratories worldwide. CAS No. 15307-77-4 | Explore complete technical documentation, Safety Data Sheet (SDS), and pricing.