Diisopropylamine → HCID 19434960, compound

Participants

Reaction Conditions

Reaction Steps

0.83 mL (5.9 mmol) of diisopropylamine was dissolved in 10 mL of tetrahydrofuran under argon atmosphere, 3.5 mL of a 1.6 M solution of n-butyl lithium in n-hexane was added dropwise under ice-cooling and the solution was cooled to -78 ° C. To this solution was added a solution of 838 mg (1.79 mmol) of the above 2-acetyl-4,5,6-trifluoro-3-pivaloylaminophenyl 4-acetylamino-3-fluorobenzoate in 20 mL of tetrahydrofuran was added dropwise and the mixture was stirred for 2 hours while the temperature of the mixture was gradually raised to 0° C. An aqueous solution of ammonium chloride was added to the reaction solution, the mixture was extracted twice with ethyl acetate, the organic layer was washed once with an aqueous saturated solution of sodium chloride and dried over anhydrous sodium sulfate. The solvent was distilied off under reduced pressure, the residue was dissolved in 24 mL of ethanol, 6 mL of concentrated hydrochloric acid was added and the mixture was stirred at room temperature for 4 hours. Water was added to the reaction solution and the precipitated crystals were collected by filtration to give 330 mg of 2-(4-acetylamino-3-fluorophenyl)-6,7,8-trifluoro-5-pivaloylamino-4H-1-benzopyran-4-one (yield: 77%).

Provenance & Evidence