Triethylamine → HCID 11130688, compound

Participants

Reaction Steps

A suspension of racemic methyl 2-(benzo[d][1,3]dioxol-5-yl)-4-hydroxychroman-3-carboxylate (49 mg, 149 μmol) in dichloromethane (2.0 mL) was stirred on an ice bath and treated with triethylamine (31 μL, 224 μmol), then dropwise with methanesulfonyl chloride (13 μL, 164 μmol). The cooling bath was removed after 90 min and the solution was stirred at rt for 23 h. At the conclusion of this period, the solution was diluted with additional dichloromethane, washed with 1.0 M aqueous HCl, dried over sodium sulfate and concentrated under vacuum to yield a residue. The residue was dissolved in benzene (2.0 mL), treated with 1,8-diazabicyclo[5.4.0]undec-7-ene (30 μL, 224 μmol) and stirred at 60° C. for 3.75 h. After this time, the mixture was cooled to rt and then diluted with ethyl acetate, washed with 1.0 M aqueous HCl, water, and saturated aqueous sodium chloride, dried over sodium sulfate and concentrated under vacuum. The resulting residue was purified by column chromatography (silica gel, 2-10% ethyl acetate/hexane) to provide racemic methyl 2-(benzo[d][1,3]dioxol-5-yl)-2H-chromene-3-carboxylate as a white solid (27 mg, 58%). 1H NMR (400 MHz, CDCl3) δ ppm 3.77 (s, 3 H) 5.91 (m, 2 H) 6.18 (s, 1 H) 6.71 (d, J=8.6 Hz, 1 H) 6.78 (d, J=8.1 Hz, 1 H) 6.85 (m, 2 H) 6.90 (t, J=7.4 Hz, 1 H) 7.19 (m, 2 H) 7.67 (s, 1 H).

Provenance & Evidence