40428-87-3

A THF solution (250 mL) of 1-bromo-3-(propan-2-yl)benzene (5.0 g, 25.11 mmol, 1.00 eq.) was added to a 500 mL round-bottomed flask protected by an inert N2 atmosphere. The reaction system was cooled to -60 °C and n-butyllithium (20 mL, 2.00 eq.) was slowly added dropwise under stirring. After the dropwise addition, stirring was continued at -60 °C for 30 min. Subsequently, the reaction system was warmed to -30 °C and N-methoxy-N-methylacetamide (3.9 g, 37.82 mmol, 1.50 eq.) was added slowly dropwise under stirring. After completion of the dropwise addition, the reaction mixture was continued to be stirred in a liquid nitrogen bath at -30 °C for 3 hours. At the end of the reaction, the reaction was quenched by adding 20 mL of water. The reaction mixture was diluted with 200 mL of ethyl acetate, washed sequentially with 2 x 100 mL of brine, and the organic phase was dried over anhydrous Na2SO4 and concentrated under reduced pressure. The residue was purified by silica gel column chromatography with ethyl acetate/petroleum ether (1:10) as eluent to give 2.7 g (66% yield) of the target product 1-(3-isopropylphenyl)ethanone as a colorless oil.

[1] Patent: WO2016/201426, 2016, A1. Location in patent: Paragraph 0243
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