The compound with CAS 187949-02-6, known chemically as 7-Chloro-3-[(2R,3R)-3-(2,4-difluorophenyl)-3-hydroxy-4-(1,2,4-triazol-1-yl)butan-2-yl]quinazolin-4(3H)-one, is a key synthetic intermediate in the production of the antifungal drug Posaconazole. Its structure features a quinazolinone core linked to a chiral side chain containing a difluorophenyl group and a 1,2,4-triazole moiety, which are pharmacophores critical for antifungal activity. As a pivotal building block, this intermediate is specifically designed for the final steps in the synthesis of Posaconazole, a broad-spectrum triazole antifungal agent used to treat severe invasive fungal infections. The precise stereochemistry at the chiral centers is essential for the drug's efficacy and binding to the fungal cytochrome P450 enzyme lanosterol 14α-demethylase, thereby inhibiting ergosterol biosynthesis in fungal cell membranes. Its primary industrial significance lies in pharmaceutical manufacturing, where it is processed under controlled conditions to yield the final active pharmaceutical ingredient (API). Handling requires standard precautions for fine chemicals, including the use of personal protective equipment to avoid inhalation or skin contact.