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 2.0 g of 2,6-difluorobenzoyl isocyanate in 10 ml of dry methylene chloride was added rapidly to a stirred solution of 4.5 g of 32 in 20 ml of the same solvent at room temperature. After stirring for 4 hours the solvent was removed under reduced pressure, and the residue was purified by chromatography twice on silica, using first methylene chloride and then diethyl ether as eluent. The product thus obtained was finally purified by crystallization from diethyl ether/light petroleum to give 35, as colourless crystals, m.p.: 98°-99° C.

Provenance & Evidence