2,6-Difluorobenzoyl isocyanate → N-[3,5-Dichloro-2-fluoro-4-(1,1,2,3,3,3-hexafluoropropoxy)phenyl]-N'-(2,6-difluorobenzoyl)-N-ethylurea

Participants

Reaction Conditions

Reaction Steps

To a solution of 1.00 g 3,5-dichloro-2-fluoro-4-(1,1,2,3,3,3-hexafluoropropoxy)-N-ethyl aniline in 2 mL 1,2-dichloroethane under an atmosphere of nitrogen at room temperature there was added 0.54 g 2,6-difluorobenzoyl isocyanate dissolved in 6 mL dichloroethane dropwise over a 10 minute period. The mixture was stirred and warmed to 40° C. for a 1.5 hour period. Analysis by thin layer chromatography silica gel 4:1 heptane/ethyl acetate indicated incomplete reaction. To the mixture was added 0.13 g 2,6-difluorobenzoyl isocyanate in 1.5 mL 1,2-dichloroethane, and the mixture was warmed at 40° C. for 2.5 hour. Analysis by TLC indicated complete reaction. The reaction mixture was concentrated under vacuum to give an oil 1.64 g, which was chromatographed using a Michel-Miller low pressure silica gel column eluted with 4:1 heptane/ethyl acetate. Like fractions were pooled and concentrated under vacuum to give a white solid 0.87 g, mp 106°-14° C. Proton nmr and mass spectra were consistent with the proposed structure. Anal. calcd C19H11Cl2F9N2O3 : C, 40.95; H, 1.99; N, 5.03. Found: C, 40.89; H, 1.92; N, 5.03.

Provenance & Evidence