Dimethyl Sulfoxide → 3-Chloro-5,5-dimethyl-2,4-hexanedione

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Reaction Steps

Chlorotrimethylsilane (26.8 ml, 0.21 mol) was added dropwise to a stirred pale yellow solution of tetrabutylammonium bromide (1.139, 3.50 mmol) in dry acetonitrile (100 ml) at room temperature under nitrogen. The resulting solution was cooled in ice and 5,5-dimethylhexane-2,4-dione (10.0 g, 70.4 mmol) and then dry dimethylsulphoxide (14.7 ml, 0.21 mol) were added dropwise over 5 minutes producing a yellow solution which was allowed to warm slowly to room temperature with stirring over 3 hours. The mixture was diluted with water (1000 ml) and stirred for 10 min and then extracted with ether (1×500 ml, 2×250 ml). The combined ether layers were dried over magnesium sulphate, filtered and concentrated under reduced pressure to leave a yellow oil. The crude product was purified by distillation under reduced pressure to provide the title compound (10.0 g) as a pale yellow oil, b.p. 220-225° C./60 mmHg.

Provenance & Evidence