Dimethylformamide → HCID 86652900, compound

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Reaction Steps

To a dry two-neck flask, compound 8 (4.3 g, 24 mmol, 1 equiv) and K2CO3 (16 g, 120 mmol, 5 equiv) were added into anhydrous DMF (50 mL) under nitrogen. The mixture was stirred at rt for 30 min. Dibromoethane (21 mL, 240 mmol, 10 equiv) was then added in one portion and the resulting mixture was heated overnight at 55° C. under a nitrogen atmosphere. The mixture was poured into water (400 mL) and the product was extracted with ethyl acetate (3×200 mL). The combined organic extracts were concentrated to about 250 mL and were washed subsequently with 1 M NaOH (2×200 mL), water (250 mL) and brine (5×250 mL). The organic layer was dried over MgSO4, filtered and the solvent was removed under vacuum. The crude product as yellow oil was chromatographed on a silica gel column with the eluent of ethyl acetate/hexane (20/80) to give pure product as a white solid (5.2 g, yield: 77%). 1H NMR δ=9.88 (s, 1H, —CHO), 7.58 (d, J=1.8, 1H), 7.54 (dd, J1=1.8, J2=8, 1H), 7.02 (d, J=8, 1H), 4.83 (d, J=2.3, 2H, —OCH2), 4.43 (t, J=6.6, 2H, —OCH2CH2Br), 3.72 (t, J=6.6, 2H, —OCH2CH2Br), 2.54 (t, J=2.3, 1H, —C≡CH). 13C NMR δ=190.68 (—CHO), 153.70, 147.77, 130.79, 127.01, 113.95, 113.19, 78.01 (—C≡CH), 76.63 (—C≡CH), 68.98 (—OCH2CH2Br), 57.16 (—OCH2C≡CH), 28.45 (—OCH2CH2Br). HRMS calculated for C12H11BrO3 (M+), 281.9892; found, 281.9903.

Provenance & Evidence