Methyl iodide → (R)-2-(5-benzyloxy-indol-1-yl)-propionic acid methyl ester

Participants

Reaction Steps

A suspension of (R)-2-(5-benzyloxy-indol-1-yl)-propionic acid (Example 4, 18.0 g, 0.061 mol), sodium bicarbonate (15.36 g, 0.183 mol), and iodomethane (11.40 mL, 0.183 mol) in DMF (164 mL) was stirred at rt for 20 h. The reaction was monitored by reverse phase HPLC. Upon completion, the reaction was quenched by pouring into ice/water (300 mL) followed by extracting with ethyl acetate (2×150 mL). The combined organic layer was washed with water (2×150 mL) and brine (150 mL) and was dried over anhydrous sodium sulfate. Filtration and concentration to dryness gave a crude oil which was purified by silica gel chromatography using 10-35% ethyl acetate/hexanes to give 16.38 g (87%) of (R)-2-(5-benzyloxy-indol-1-yl)-propionic acid methyl ester as an oil. 1H NMR (DMSO-d6) δ 7.4 (d, 2H), 7.3 (m, 3H), 7.3 (m, 2H), 7.1 (s, 1H), 6.82 (d, 1H), 6.38 (s, 1H), 5.41 (q, 1H), 5.08 (s, 2H), 3.60 (s, 3H), 1.70 (d, 3H); LC/MS (+esi) m/z 310.2 (M+H)+, RT 3.47 min.

Provenance & Evidence