C([Li])CCC.[Cl:6][C:7]1[CH:12]=[C:11]([C:13]([F:16])([F:15])[F:14])[CH:10]=[C:9]([Cl:17])[C:8]=1Br.Cl[C:20]([O:22][CH2:23][CH3:24])=[O:21].[Cl-].[NH4+]>CCOCC>[Cl:6][C:7]1[CH:12]=[C:11]([C:13]([F:16])([F:15])[F:14])[CH:10]=[C:9]([Cl:17])[C:8]=1[C:20]([O:22][CH2:23][CH3:24])=[O:21]
n-Butyllithium (1.6M in hexane, 330 ml) was added dropwise with stirring to a solution of 2,6-dichloro-4-trifluoromethylbromobenzene (163.3 g) in ether while maintaining the temperature below -70° C. The mixture was stirred for 1 hour at -78° C. then ethyl chloroformate (61.7 g) was added while maintaining the temperature below -70° C. The mixture was stirred at room temperature overnight. It was cooled to 0° C. and a saturated aqueous solution of ammonium chloride was added. The layers were separated and the organic layer was washed with water, dried (Na2SO4) and filtered. The filtrate was evaporated to dryness and the residue was distilled to give ethyl 2,6-dichloro-4-trifluoromethylbenzoate (123.9 g) as a colourless liquid bp 90°-96° C. at 5 mmHg.
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