反应详情

n-Butyl lithium (12.9 ml of a 1.6 M solution in hexane) was added dropwise to a solution of 3-bromo-2,4,5,6-tetrafluorotoluene (5.0 g) in diethyl ether (40 ml) under an argon atmosphere whilst maintaining the mixture temperature within the range -60° to -70° C. When the addition was complete the mixture was stirred for a period of 1.5 hours at -70° C. after which a solution of N-methylformanilide (2.8 g) in diethyl ether (15 ml) was added and the resultant mixture allowed to attain the ambient temperature (ca. 25° C.). Dilute hydrochloric acid (25 ml) of a 2 N solution) was added to the well-stirred mixture after which the ethereal layer was separated, washed with water and dried over anhydrous magnesium sulphate. After removal of the solvent by evaporation under reduced pressure the residual oil was distilled to yield 3-methyl-2,4,5,6-tetrafluorobenzaldehyde (1.6 g) b.p. 78°-80° C./14 mm Hg.

1. temperaturewhilst maintaining the mixture temperature within the range -60° to -70° C
2. additionWhen the addition
3. additionwas added
4. customthe ambient temperature (ca. 25° C.)
5. customwas separated
6. washwashed with water
7. dry with materialdried over anhydrous magnesium sulphate
8. customAfter removal of the solvent
9. customby evaporation under reduced pressure the residual oil
10. distillationwas distilled