5-chloro-N-methoxy-N-methyl-1H-indole-2-carboxamide → 1-(5-chloro-1H-indol-2-yl)pentan-1-one

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Reaction Steps

To a cooled (−78° C.) solution of the title compound of Example 1 Step A (2.40 g, 10.1 mmol) in THF (30 mL) was added n-BuLi (15.7 mL, 1.6 M in hexanes, 25.1 mmol), and the mixture was stirred for 1.5 h, whereupon it was transferred to a 0° C. bath. After 45 min, the reaction mixture was quenched by addition of 2 N aq. HCl. The aqueous phase was extracted with EtOAc, and the organic phase was dried over anhydrous Na2SO4 and concentrated in vacuo. Purification by flash chromatography on silica gel (0 to 25%, then 25 to 100% EtOAc in hexanes) provided the title compound: LCMS A, tr=3.74 min, m/z 236.1 [M+H]+; 1H NMR (500 MHz, CDCl3) □9.34 (br s, 1H), 7.68 (d, J=2.0 Hz, 1H), 7.37 (d, J=8.5 Hz, 1H), 7.29 (dd, J=8.5, 1.5 Hz, 1H), 7.13 (d, J=1.5 Hz, 1 H), 2.95 (t, J=7.5 Hz, 2H), 1.80-1.74 (m, 2H), 1.47-1.40 (m, 2H), 0.97 (t, J=7.5 Hz, 3H).

Provenance & Evidence