To a stirring solution of 1,3-dibromo-5-tert-butylbenzene (5.0 g, 17.0 mmol) in dry ether at ?78°C, n-Butyllithium (1.1 equiv.) was added dropwise. After stirring for 30 min under the N2 atmosphere, N-methoxy-N-methylacetamide (2.4 ml, 22.1 mmol) was added dropwise. The reaction mixture was allowed to warm to room temperature and stirred for 12 h. After quenching with a saturated solution of ammonium chloride, water was added, and the mixture was extracted with ether (2 × 150 ml). The combined organic extracts were washed with water (2 × 200 ml), dried with MgSO4 and evaporated to give a crude product. Purification was done by silica gel flash column chromatography using ethyl acetate: n-hexane mixture (v:v = 1:28) as eluent to give 1-(3-bromo-5-(tert-butyl)phenyl)ethanone as pale yellow oil.
