Cesium carbonate → 2-[(1-Benzyl-2-ethyl-6,7,8,9-tetrahydro-1h-benz[g]indol-4-yl)oxy]acetic acid methyl ester

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Reaction Steps

A solution of 1-benzyl-2-ethyl-4-methoxy-6,7,8,9-tetrahydro-1H-benz[g]indole (660 mg, 2.07 mmol) in methylene chloride (10 mL) was cooled to 0° C. and treated with boron tribromide (0.38 mL, 4.0 mmol). The mixture was stirred for 10 min, poured into ice water, and extracted twice with methylene chloride. The combined methylene chloride layers were washed once with saturated sodium bicarbonate solution, dried (sodium sulfate), filtered, and concentrated in vacuo. The residue was dissolved in N,N-dimethylformamide (10 mL) and treated with cesium carbonate (652 mg, 2.00 mmol) and methyl bromoacetate (0.28 mL, 2.0 mmol) at room temperature for 3 h. The mixture was diluted with water and extracted three times with ether. The combined ether extracts were washed once with water, dried (magnesium sulfate), filtered, and concentrated in vacuo. Chromatography (silica gel, methylene chloride) provided 479 mg (62%) of the title compound as an off-white solid. 1H NMR (CDCl3) δ 7.25 (m, 3H), 6.85 (d, J=7.6 Hz, 2H), 6.52 (s, 1H), 6.16 (s, 1H), 5.57 (s, 2H), 4.79 (s, 2H), 3.86 (s, 3H), 2.97 (m, 2H), 2.84 (m, 2H), 2.59 (q, J=7.3 Hz, 2H), 1.72 (m, 4H), 1.32 (t, J=7.3 Hz, 3H); MS ES+ m/e 378 (p+1); IR (CHCl3, cm1) 2830, 1756, 1732.

Provenance & Evidence