Our 3-(4-Chlorophenyl)Isoindolin-1-one is a high-purity crystalline intermediate belonging to the isoindolinone family. This compound is an essential "platform molecule" used in the multi-step synthesis of various tricyclic sympathomimetic agents, most notably Mazindol. Specialised heterocyclic organic building block primarily utilised as a high-value pharmaceutical intermediate & recognised as a key precursor in the synthesis of Mazindol (a potent anorexiant/appetite suppressant) and is also a documented impurity standard for the diuretic medication Chlorthalidone. In 2026, Phthalimidine, 3-(p-chlorophenyl)- is also highly sought after by quality control laboratories as a reference standard for Chlorthalidone impurity profiling. Featuring a robust chemical structure with a chlorophenyl substitution, it provides a stable foundation for a broad spectrum of biological activities, including antimicrobial and anxiolytic research. We offer this product at 98%+ purity, backed by comprehensive analytical data (NMR, HPLC) to support global API manufacturing and research requirements. We are globally established pharmaceutical suppliers, right from intermediate to semi-finished formulations / dosages, ensuring reliable lead times; comprehensive regulatory documentation (CoA); and consistent worldwide supply capabilities across all grades/forms/strengths.