Indole-5-carboxaldehyde → tert-Butyl 5-formyl-1H-indole-1-carboxylate

Participants

Reaction Steps

5-Formylindole (1.45 g, 10.0 mmol) and 4-dimethylaminopyridine (1.47 g, 12.0 mmol) were dissolved in acetonitrile (20 mL) with stirring at ambient temperature. Once dissolution was complete, the reaction mixture was cooled to −10° C. with stirring. Di-t-butylcarbonate (2.18 g, 10.0 mmol) was added in one portion. Stirring was continued for 2 h. The reaction mixture was diluted with EtOAc (50 mL) and the organic solution was washed successively with water (20 mL), a 1N HCl solution (10 mL), a saturated NaHCO3 solution (20 mL) and brine (20 mL). The organic solution was dried over MgSO4 and filtered. Solvent was removed in vacuo from the filtrate to provide a pale yellow oil (2.45 g, 100% yield): 1H NMR (CDCl3, 300 MHz): 10.1 (s, 1H), 8.31 (d, 1H, J=8), 8.12 (s, 1H), 7.87 (dd, 1H, J=8, 1), 7.70 (d, 1H, J=4), 6.71 (d, 1H, J=4), 1.71 (s, 9H).

Provenance & Evidence