Reaktion #2252531

Reaktionsgleichung

triethyl amine

2,4-difluoroaniline

2-chloro-4,5-difluorobenzoic acid

→

2-(2,4-difluorophenylamino)-4,5-difluorobenzoic acid

Ausbeute 63.1%

Lösungsmittel

DMF

DMF

Reaktionsbedingungen

Aufarbeitung

1. 1
   Temperaturto cool to room temperature
2. 2
   SonstigeThe reaction mixture was evaporated in vacuo
3. 3
   Sonstigethe residue was partitioned between ether and aqueous ammonium chloride
4. 4
   WaschenThe organic phase was washed with 2N HCl and saturated aqueous lithium chloride solution
5. 5
   TrocknenThe ether was dried over sodium sulfate
6. 6
   workup.ADDITIONtreated with darco
7. 7
   Filtrationfiltered
8. 8
   Sonstigeevaporated
9. 9
   SonstigeThe residue was crystallized from hexane-ether

Vorschrift

A suspension of triethyl amine (15 ml, 0.11 mol), 2,4-difluoroaniline (25 ml, 0.24 mol), copper bronze (2.7 g., 0.04 mol), in hot DMF (25 ml) was treated with a solution of 2-chloro-4,5-difluorobenzoic acid (23 g., 0.12 mol) in 25 ml of DMF and the temperature was maintained at 85° C. for 8 hours. The reaction mixture was allowed to cool to room temperature and was then stirred overnight. The reaction mixture was evaporated in vacuo and the residue was partitioned between ether and aqueous ammonium chloride. The organic phase was washed with 2N HCl and saturated aqueous lithium chloride solution. The ether was dried over sodium sulfate, treated with darco and then filtered and evaporated. The residue was crystallized from hexane-ether to afford 21.6 g (62%) of 2-(2,4-difluorophenylamino)-4,5-difluorobenzoic acid; m.p.: 215°-216° C.

Quelle