Dimethyl Sulfoxide → p-Chlorocinnamaldehyde

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

A solution of oxalyl chloride (2.6 mL, 30 mmol) in methylene chloride was cooled to −70° C. in a dry ice/acetone bath and DMSO (4.2 mL, 60 mmol) was added slowly. After 10 minutes, a solution of 4-chlorocinnamyl alcohol (2.0 g, 12 mmol) from Step A in methylene chloride (12 mL) was added. The reaction was stirred at −70° C. for 80 min and then DIPEA (20 mL, 120 mmol) was added. After 5 min, the reaction was allowed to warm to rt over 2 h. The mixture was diluted with methylene chloride and washed with cold 2N hydrochloric acid (80 mL). The organic layer was washed with brine containing some aq. sodium bicarbonate, dried over sodium sulfate, and evaporated. The residue was purified by FC (0 to 10% ethyl acetate in hexanes) to give the title compound as a white solid. 1HNMR (CDCl3): δ 6.71 (dd, J=7.7 and 16.0 Hz, 1H), 7.450 (d, J=16 Hz, 1H), 7.43 and 7.52 (Abq, J=8.4 Hz, 4H), 9.72 (d, J=7.6 Hz, 1H).

Herkunft & Nachweise