5-Bromo-2-chlorobenzoic acid → 5-bromo-2-chloro-N-cyclopropylbenzamide

Beteiligte Stoffe

Reaktionsschritte

To a suspension of 5-bromo-2-chlorobenzoic acid (17.6 g, 75 mmol) in CH2Cl2 (180 mL) was added oxalyl chloride (7.0 mL, 83 mmol). DMF (8 drops) was added, and the mixture was stirred for 2 h at rt (gas evolution). The mixture was reduced under reduced pressure, and the crude residue was diluted with CH2Cl2 (530 mL). The mixture was cooled to 0° C., and a sol. of cyclopropylamine (5.8 mL, 83 mmol) in CH2Cl2 (45 mL) was added dropwise. The mixture was stirred for 10 min at 0° C., and was allowed to warm to rt. DIPEA (14.3 mL, 84 mmol) was added, and the mixture was stirred for 2 h at rt. The mixture was diluted with more CH2Cl2, and was washed with aq. 10% HCl, water, and brine. The org. layer was dried over MgSO4, filtered, and the solvents were removed under reduced pressure. The residue was triturated with hexane, filtered, and dried under high vacuum to yield the title compound (19.3 g, 94%). LC-MS: tR=0.84 min; ES+: 316.89.

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