Piperidine → 5-Methoxyoxindole

Participants

Reaction Conditions

Reaction Steps

5-Methoxyindolin-2-one was prepared by the method of Crestini, C.; Saladino, R. Synth. Commun. (1994), Vol. 24, NO. 20, p. 2835. A solution of 5-methoxyindolin-2-one (0.41 g, 2.5 mmol) and 2-pyrrolecarboxaldehyde (0.25 g, 2.6 mmol) in ethanol (5 mL) was treated with piperidine (0.05 g, 0.65 mmol). The reaction mixture was then heated to 85° C. for 3 hours. The reaction was then cooled to ambient temperature and the reaction mixture was chromatographed on SiO2 (12 g) using 3:1 hexane/ethyl acetate to afford 5-methoxy-3-[(pyrrol-2-yl)methylene]indolin-2-one; (0.48 g); 1H NMR (400 MHz, DMSO-d6) δ 3.74 (s, 3H), 6.30 (m, 1H), 6.60–6.80 (m, 3H), 7.30 (m, 1H), 7.35 (m, 1H), 7.76 (m, 1H), 10.80 (s, 1H) ppm.

Provenance & Evidence