2,6-Difluorobenzoyl isocyanate → Propyl 4-[4-[2-chloro-4-(trifluoromethyl)phenoxy]-2-fluorophenyl]-7-(2,6-difluorophenyl)-2-methyl-5,7-dioxo-3-thia-2,4,6-triazaheptanoate

Participants

Reaction Steps

A solution of 2,6-difluorobenzoyl isocyanate (2.0 g) in dry methylene chloride (10 ml) was added rapidly to a stirred solution of the compound of Example 2 (4.5 g) in the same solvent (20 ml) at room temperature. After stirring for 4 hours the solvent was removed under reduced pressure, and the residue was purified by chromatography (2x) on silica, using first methylene chloride and then diethyl ether as eluant. The product thus obtained was finally purified by crystallisation from diethyl ether/light petroleum affording colourless crystals (4.5 g) melting at 98°-99° C.

Provenance & Evidence