2,6-Difluorobenzoyl isocyanate → Benzamide

Reaktionsgleichung

[F:1][C:2]1[CH:12]=[CH:11][CH:10]=[C:9]([F:13])[C:3]=1[C:4]([N:6]=[C:7]=[O:8])=[O:5].[Cl:14][C:15]1[C:21]([C:22]([F:25])([F:24])[F:23])=[CH:20][C:19]([C:26]([F:29])([F:28])[F:27])=[CH:18][C:16]=1[NH2:17]>ClCCCl>[C:4]([NH2:6])(=[O:5])[C:3]1[CH:9]=[CH:10][CH:11]=[CH:12][CH:2]=1.[Cl:14][C:15]1[C:21]([C:22]([F:24])([F:25])[F:23])=[CH:20][C:19]([C:26]([F:27])([F:28])[F:29])=[CH:18][C:16]=1[NH:17][C:7]([NH:6][C:4](=[O:5])[C:3]1[C:2]([F:1])=[CH:12][CH:11]=[CH:10][C:9]=1[F:13])=[O:8]

Komponenten

Versuchsvorschrift

In order to synthesize the isocyanate, 1.57 g (10 mmol) of 2,6-difluorobenzamide and 15 ml of dry 1,2-dichloroethane were introduced into a 100 ml flask and then 0.92 g (10.5 mmol) of oxalyl chloride was slowly added thereto at normal temperature by means of a syringe, during which an exothermic reaction occurred that generated hydrochloride gas. The resulting reaction mixture was refluxed for 5 hours and cooled to normal temperature. The reaction solvent and the excess oxalyl chloride were removed therefrom under vacuo to obtain 2,6-difluorobenzoyl isocyanate in an oily state. Thus obtained 2,6-difluorobenzoyl isocyanate was then dissolved in 20 ml of dry 1,2-dichloroethane. Then, 2.63 g of 2-chloro-3,5-bis(trifluoromethyl)aniline was added thereto, reacted for 3 hours, and filtered to obtain 4.15 g (Yield from benzamide, 93%) of the title compound as a solid.