Hydrochloric Acid → 5-Hydroxy-2-(4-hydroxy-phenyl)-benzofuran-4-carbonitrile

HRID 1836052Notes

Reaction equation

C[O:2][C:3]1[C:19]([C:20]#[N:21])=[C:7]2[CH:8]=[C:9]([C:11]3[CH:16]=[CH:15][C:14]([O:17]C)=[CH:13][CH:12]=3)[O:10][C:6]2=[CH:5][CH:4]=1.Cl.N1C=CC=CC=1.Cl>C(OCC)(=O)C>[OH:2][C:3]1[C:19]([C:20]#[N:21])=[C:7]2[CH:8]=[C:9]([C:11]3[CH:12]=[CH:13][C:14]([OH:17])=[CH:15][CH:16]=3)[O:10][C:6]2=[CH:5][CH:4]=1

Participants

Conditions

Temperature: 200 °C

Procedure

5-Methoxy-2-(4-methoxyphenyl)-benzofuran-4-carbonitrile 134 (0.088 g, 0.31 mmol) was placed in a sealed tube along with pyridine hydrochloride (enough to fill the volume of the tube by one-half) and heated at 200° C. for 2.5 hours. The reaction was dissolved into a mixture of ethyl acetate and 1N HCl. The layers were separated and the aqueous layer was extracted with ethyl acetate (2×). The combined organics was washed with 1N HCl (1×), water (1×) and then dried over magnesium sulfate, filtered and concentrated. The resulting material was purified by column chromatography, using 40% ethyl acetate in hexanes as the eluent to yield the desired product 135 (0.066 g, 84.7%) as a light brown solid: Mp>230° C.; 1H NMR (DMSO-d6) δ 10.89 (s, 1 H), 10.03 (s, 1 H), 7.82 (d, 2 H, J=8.6 Hz), 7.72 (d, 1 H, J=8.9 Hz), 7.27 (s, 1 H), 6.90 (d, 2 H, J=8.6 Hz), 6.88 (d, 1 H, J=8.9 Hz).

Workup

customThe layers were separated
extractionthe aqueous layer was extracted with ethyl acetate (2×)
washThe combined organics was washed with 1N HCl (1×), water (1×)
dry with materialdried over magnesium sulfate
filtrationfiltered
concentrationconcentrated
customThe resulting material was purified by column chromatography

Sources & evidence

ORD record: ord-d8e08130d23847f2aec9dae47ef3fd85
Source dataset: uspto-grants-2004_08
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US06774248B2

Reaction notes

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