Methanol → tert-butyl 3-formyl-1H-indole-1-carboxylate

Participants

Reaction Steps

Indole-3-carboxaldehyde (4.53 g, 30 mmol) was dissolved in tetrahydrofuran (100 mL) (dissolved at about 40° C.). Aqueous potassium hydroxide (1N, 30 mL) and tetrabutylammonium bromide (0.97 g, 3 mmol) were added. Then di-t-butylcarbonate (7.2 g, 33 mmol) was added (the temperature should not rise about 25° C.). The resulting mixture was stirred at room temperature until the starting material was not detected by TLC (CH2CL2 /CH3OH 9:1). The reaction mixture was separated, and the aqueous layer was extracted with ethyl acetate (2×50 mL). The combined organic layer was dried with MgSO4 and evaporated to give crude product. The product was recrystallized from methylene chloride/hexane (20 mL/100 mL) to obtain needle crystals (7.19 g, 97.7%). m.p. 124°-125° C.

Provenance & Evidence