Dimethylformamide → 6-bromo-N-methyl-2-naphtamide

Participants

Reaction Steps

6-Bromo-2-naphthoic acid (10.1 g, 40.1 mmol) and N,N-dimethylformamide (4.75 g, 65.0 mmol) were added to toluene (80 mL). To the reaction mixture was added dropwise thionyl chloride (5.7 g, 48.2 mmol) at 45 to 50° C., and the mixture was stirred for 1 hr, and allowed to cool to room temperature. The reaction mixture was added dropwise at 10 to 25° C. to a solution prepared by adding triethylamine (11.4 g, 112.4 mmol) and 40% methylamine methanol solution (8.1 g, 104.4 mmol) to toluene (80 mL), and the mixture was stirred at room temperature for 1 hr. To the reaction mixture was added dropwise water (50 mL), and the mixture was stirred at room temperature. The crystals were collected by filtration, and washed with a mixed solvent (25 mL) of methanol/water (2:8) to give wet crystals. The total amount of the wet crystals was added to N,N-dimethylacetamide (70 mL), and dissolved with heating to 60° C. The reaction mixture was allowed to cool to room temperature, and water (140 mL) was added dropwise thereto. The crystals were collected by filtration, and washed with water (80 mL) to give wet crystals. The total amount of the wet crystals was suspended in ethyl acetate (25 mL) with stirring at room temperature. The crystals were collected by filtration, and washed with ethyl acetate (5 mL). The obtained wet crystals were dried under reduced pressure to give 6-bromo-N-methyl-2-naphthamide (9.4 g, 35.6 mmol). yield 89%.

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