N-(3-Bromo-2-methyl-6-nitrophenyl)-2,2,2-trifluoroacetamide synthesis

Yield:1325729-87-0 74%

Reaction Conditions:

Stage #1: 3-bromo-2-methylaniline;trifluoroacetic anhydride in dichloromethane at 0; for 0.5 h;
Stage #2: with potassium nitrate in dichloromethane at 0 - 20;

Steps:

Intermediate 13; 4-bromo-3-methylbenzene-l,2-diamineIntermediate 13A; A^-(3-bromo-2-methyl-6-nitrop ienyl)-2,2,2-trifluoroacetamide; To a solution of 3-bromo-2-methylaniline (1.0 g, 5.37 mmol) in CH2CI2 (4.0 mL) at 0 °C was added trifluoroacetic anhydride (2.0 mL, 14.2 mmol). The mixture was stirred at 0 °C for 30 minutes, and solid potassium nitrate (0.679 g, 6.72 mmol) was added. The cooling bath was removed, and the mixture was stirred at room temperature overnight. LCMS showed a single product formed. The mixture was concentrated in vacuo, and the residue was partitioned between water and CH2CI2 (2^χ). The organic layers were combined and dried over Na₂S04. The drying agent was filtered off and the crude product was purified by crystallization from aq EtOH to give the title compound (1.3 g, 74%).

References:

WO2012/83170,2012,A1 Location in patent:Page/Page column 156