1-Heptanol, 7-bromo- → 7-Bromoheptanoic acid

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Reaction Steps

2 N Jones' reagent (20 ml) was gradually and dropwise added to an acetone (20 ml) solution of 7-bromoheptanol (1.95 g, 10 mmols) with cooling with ice, and then stirred at room temperature for 10 minutes. The reaction mixture was extracted three times with ether (80 ml). The organic layer was washed with water, and then extracted three times with an aqueous saturated solution of sodium hydrogencarbonate (120 ml). The aqueous layers were combined, then made acidic (pH=1) with 5% sulfuric acid added thereto, and extracted with ethyl acetate. The resulting organic layer was washed with water and saturated saline in that order, and dried with anhydrous sodium sulfate, and the solvent was evaporated. 1.45 g (70%) of 7-bromoheptanoic acid was obtained as colorless needle-like crystals. WSC (891 g, 4.7 mmols) and HOBt (628 g, 4.7 mmols) were added to a DMF (20 ml) solution of the resulting carboxylic acid (1.06 g, 5 mmols) and 2,6-diisoproylaniline (738 g, 4.2 mmols), and stirred at room temperature for 12 hours. The reaction mixture was extracted with ether. The organic layer was washed with water, 1 N HCl, an aqueous saturated solution of sodium hydrogencarbonate and saturated saline in that order, and dried with anhydrous magnesium sulfate, and the solvent was evaporated. Then, the residue was purified through silica gel column chromatography (developer: hexane/acetone=5/1), and the resulting crystals were recrystallized from ether-hexane to obtain 466 g (yield: 30%) of 7-bromo-N-(2,6-diisopropylphenyl)heptanamide as colorless needle-like crystals.

Provenance & Evidence