反应详情

A suspension containing 27.0 g of 2,4,5-trifluoro-3-methyl-6-nitrobenzoic acid, 19.5 ml of oxalyl chloride, 270 ml of methylene chloride, and a few drops of N,N-dimethylformamide was stirred at room temperature for 2 hours. The reaction mixture was concentrated under reduced pressure to give 2,4,5-trifluoro-3-methyl-6-nitrobenzoyl chloride. Separately, a few drops of carbon tetrachloride was added to a suspension of 3.08 g of magnesium in 6.4 ml of absolute ethanol, and then a solution of 19.2 ml of diethyl malonate in 12 ml of absolute ethanol was added dropwise to the suspension under heating at 50° C., and the mixture was stirred at the same temperature for 1.5 hours. The reaction mixture was concentrated under reduced pressure, and then, toluene was added to dissolve the residue and the solution was again concentrated. To a solution of the residue in 30 ml of toluene, a solution of 2,4,5-trifluoro-3-methyl-6-nitrobenzoyl chloride in 30 ml of toluene was added dropwise with stirring under ice cooling, and then stirring was continued for 2 hours at room temperature. The reaction mixture was added with 100 ml of 5% sulfuric acid, and was then extracted with diethyl ether. The extract was washed with brine, and then dried and concentrated to give 47.3 of brown oil.

1. concentrationThe reaction mixture was concentrated under reduced pressure