N-bromobutanimide → Methyl 4-bromomethyl-2,6-diacetoxybenzoate

Participants

Reaction Steps

Methyl 4-methyl-2,6-diacetoxybenzoate (14.9 grams, 56.0 mmoles) was dissolved in carbon tetrachloride (200 mL), and N-bromosuccinimide (11.1 grams, 62.2 mmoles) and benzoyl peroxide (0.2 grams, 0.8 mmoles) were added. The mixture was refluxed under nitrogen. After 3.5 hours, an additional portion (0.2 grams) of N-bromosuccinimide was added. Reflux was continued for an additional hour. The reaction mixture was cooled to room temperature and then in ice for 1 hour, and the solid removed by filtration. The filtrate was evaporated to dryness. Hexanes (250 mL) was added to the residue, and the mixture was boiled until dissolution was obtained. The hexanes solution was concentrated to about 75 mL when a solid just began to precipitate. The mixture was heated to dissolve the solid, and the solution was allowed to cool slowly to room temperature. White crystals formed slowly, and the mixture was chilled in ice for 2 hours to complete crystallization. The solid was filtered, washed with cold hexanes (100 mL), and dried in vacuo to afford 11.9 grams (62% yield) of methyl 4-bromomethyl-2,6-diacetoxy-benzoate (m.p. 93°-95° C., open capillary, uncorrected). The product was contaminated with a small amount of methyl 2,6-diacetoxy-4-dibromomethylbenzoate, which did not interfere with subsequent reactions.

Provenance & Evidence