Hydrochloric Acid → 4-Cyano-7-hydroxy benzo[b]thiophene

HRID 1822973Notes

Reaction equation

[C:1]([C:3]1[C:11]2[CH:10]=[CH:9][S:8][C:7]=2[C:6]([O:12]C)=[CH:5][CH:4]=1)#[N:2].C([S-])C.[Na+].C(OCC)(=O)C.Cl>CN(C=O)C>[C:1]([C:3]1[C:11]2[CH:10]=[CH:9][S:8][C:7]=2[C:6]([OH:12])=[CH:5][CH:4]=1)#[N:2]

Participants

Conditions

Temperature: 150 °C

Procedure

To a solution of 4-cyano-7-methoxy benzo[b]thiophene (450 mg, 2.38 mmol, 1 equiv.) in dry DMF (20 mL) was added sodium ethanethiolate (80% technical grade, 1.34 g, ˜13 mmol, ˜5 equiv.) and the reaction mixture was heated at 150° C. for 2 hr. The mixture was cooled to room temperature and ethyl acetate and 1N HCl were added and the layers were separated. The aqueous layer was extracted with ethyl acetate and the combined organic extracts were washed with brine (3 times), dried over anhydrous magnesium sulfate, filtered, and concentrated under reduced pressure. The acquired material thus obtained was purified via medium pressure liquid chromatography eluting with 30% ethyl acetate/70% hexanes to afford the title compound (414 mg, 99%) as a colorless solid; □H (400 MHz, CD3OD) 6.80 (1H, d, J=8 Hz), 7.47 (1H, d, J=6 Hz), 7.64 (1H, d, J=8 Hz), 7.83 (1H, d, J=6 Hz).

Workup

temperatureThe mixture was cooled to room temperature
customthe layers were separated
extractionThe aqueous layer was extracted with ethyl acetate
washthe combined organic extracts were washed with brine (3 times)
dry with materialdried over anhydrous magnesium sulfate
filtrationfiltered
concentrationconcentrated under reduced pressure
customThe acquired material thus obtained
customwas purified via medium pressure liquid chromatography
washeluting with 30% ethyl acetate/70% hexanes

Sources & evidence

ORD record: ord-e55a3dc0c97448aab0497a7a63ac9f13
Source dataset: uspto-grants-2006_05
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US07037932B2

Reaction notes

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