Water → 2-(1H-Pyrrol-1-Yl)Phenol

Participants

Reaction Conditions

Reaction Steps

A 5 L 3-neck round bottom flask was fitted with a mechanical stirrer, a heating mantle, a water cooled reflux condenser, a temperature probe/controller and a nitrogen inlet/outlet. The vessel was charged with (50 g, 0.46 mol) of 2-aminophenol and acetic acid (750 mL) which provided a very dark solution. Stirring was commenced and the vessel was charged with 2,5-dimethoxytetrahydrofuran (59.4 mL, 0.458 mol) dropwise over 2 minutes. The dark mixture was then heated at 100° C. for 15 min. The mixture was allowed to cool to room temperature and was filtered through a pad of Celite to remove residual solids. The filtrate was concentrated under reduced pressure azeotroping with toluene. The residual oil was dissolved in ethyl acetate (1000 mL) and was partitioned with water (500 mL). The organic layer was separated and was washed with water (500 mL), dried over sodium sulfate and filtered. The filtrate was concentrated under reduced pressure to provide 2-(1H-pyrrol-1-yl)phenol (54 g, 74%) as a dark oil. ESI-MS m/z calc. 159.1. found 160.2 (M+1)+. Retention time: 2.67 minutes (3 min run). 1H NMR (400 MHz, CDCl3) δ 7.37-7.23 (m, 2H), 7.13-6.97 (m, 2H), 6.91 (t, J=1.9 Hz, 2H), 6.43 (t, J=1.9 Hz, 2H), 5.35 (s, 1H). 3-(1H-Pyrrol-1-yl)pyridin-2-ol was also synthesized using the procedure described above.

Provenance & Evidence