Indole → HCID 59802492, compound

Participants

Reaction Steps

To a one liter round bottom flask equipped with a reflux condenser was added 26.3 grams (0.135 mol) of 7-chloro-1H-indole-6-carboxylic acid and 200 mL of dry methanol. Three equivalents (41.8 mL, 0.404 mol) of cyclohexanone was added in one portion. The heterogeneous mixture was heated to 60° C. at which point all of the indole went into solution. 6.1 equivalents of a methanolic sodium methoxide solution (0.820 mol, 187 mL) was then added in two portions. The solution was heated at reflux overnight. In the morning, the reaction mixture was cooled and evaporated to dryness. The crude mixture was diluted with 75 mL of ethyl acetate and acidified with 1M HCl. The resulting solid was filtered, washed with cold ethyl acetate and dried overnight in a vacuum desiccator to yield 32.8 grams (88%) of a powder. 1H NMR (300 MHz, CD3OD) δ 7.73 (d, J=8.42 Hz, 1H), 7.61 (d, J=8.42 Hz, 1H), 7.37 (s, 1H), 6.16 (br s, 1H), 2.42 (m, 2H), 2.24 (m, 2H), 1.79 (m, 2H), 1.68 (m, 2H), MS m/z 276.01 (M+H).

Provenance & Evidence