Ethyl chloroformate → Ethyl 2,6-dichloro-4-(trifluoromethyl)benzoate
Reaction equation
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]Participants
Conditions
- Temperature
- -78 °C
Procedure
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-dichloro4-trifluoromethylbenzoate (123.9 g) as a colourless liquid bp 90°-96° C. at 5 mmHg.
Workup
- temperaturewhile maintaining the temperature below -70° C
- temperaturewhile maintaining the temperature below -70° C
- stirringThe mixture was stirred at room temperature overnight
- temperatureIt was cooled to 0° C.
- customThe layers were separated
- washthe organic layer was washed with water
- dry with materialdried (Na2SO4)
- filtrationfiltered
- customThe filtrate was evaporated to dryness
- distillationthe residue was distilled
Sources & evidence
- ORD record
- ord-c0b6de3b67f84c83919b719ac23c1a22
- Source dataset
- uspto-grants-1997_08
- Patent number
- US05656573
Reaction notes
Loading…