methyl 1H-indole-5-carboxylate → methyl 2,3-dihydro-1H-indole-5-carboxylate

Beteiligte Stoffe

Reaktionsschritte

sodium cyanoborohydride (0.16 g, 2.57 mmol) was added to a solution of methyl indole-5-carboxylate (9) (0.30 g, 1.71 mmol) in AcOH (2 mL) at 0° C. The reaction mixture was warmed to room temperature and stirred for 2 h before it was quenched with water at 0° C. Concentrated NaOH was added to reach pH=10. The aqueous layer was extracted with CH2Cl2 (15 mL×3). The combined organic layer was dried over anhydrous MgSO4 and concentrated under reduced pressure to give a yellow residue, which was purified by silica gel chromatography (EtOAc:n-hexane=1:2) to afford 10 (0.28 g). 1H NMR (500 MHz, CDCl3): δ 3.06 (t, J=8.5 Hz, 2H), 3.65 (t, J=8.5 Hz, 2H), 3.84 (s, 3H), 6.53-6.55 (m, 1H), 7.75-7.76 (m, 2H).

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