Dimethylformamide → N-cyclopentylmethyl-3-formylindole-6-acetamide

Participants

Reaction Steps

N,N-dimethylformamide (0.53 ml) was cooled to 0° under an atmosphere of nitrogen and treated with phosphorus oxychloride (0.17 ml). This solution was stirred at 0° for 15 min and treated with a solution of N-cyclopentylmethylindole-6-acetamide (Example 1, part h), (0.40 g) in N,N-dimethylformamide (4 ml). The yellow mixture was stirred for 30 min and then brought to pH 14 by the addition of ice and 20% (w/v) aqueous sodium hydroxide. The mixture was heated to reflux for 5 min and allowed to cool. The precipitate which formed was collected by filtration to give N-cyclopentylmethyl-3-formylindole-6-acetamide (0.26 g, 58%) as a tan powder; partial NMR (80 MHz, DMSO-d6): 2.96(t, 2H, NHCH2), 3.48(s, 2H, COCH2), 7.21(dd, 1H, H5 -indole), 7.38(br s, 1H, H2 -indole), 9.88(s, 1H, CHO).

Provenance & Evidence