Citric Acid → HCID 86593874, compound

HRID 1271843Notes

Reaction equation

[OH:1][C:2]1[CH:13]=[CH:12][C:5]2[S:6][C:7]([C:9]([OH:11])=[O:10])=[CH:8][C:4]=2[CH:3]=1.N1C=CC=CC=1.[C:20](Cl)(=[O:27])[C:21]1[CH:26]=[CH:25][CH:24]=[CH:23][CH:22]=1.C(O)(=O)CC(CC(O)=O)(C(O)=O)O>ClCCl.C(O)(=O)C.ClCCl.CO>[C:20]([O:10][C:9]([C:7]1[S:6][C:5]2[CH:12]=[CH:13][C:2]([OH:1])=[CH:3][C:4]=2[CH:8]=1)=[O:11])(=[O:27])[C:21]1[CH:26]=[CH:25][CH:24]=[CH:23][CH:22]=1

Participants

Conditions

Temperature: 0 °C

Procedure

To a suspension of 1168 mg (6.01 mmol) 5-Hydroxy-benzo[b]thiophene-2-carboxylic acid (Misra, T., et al., Spectrochim. Acta Part A 57 (2001) 2795–2808) in 30 ml dichloromethane were added 1186 mg (15 mmol) pyridine. The mixture was cooled to 0° C. and a solution of 1968 mg (14 mmol) benzoyl chloride in 15 ml dichloromethane was added within 0.5 h. The reaction mixture was warmed to room temperature and added to 5% aqueous citric acid. The aqueous phase was extracted twice with dichloromethane, the solvent of the organic phases was removed and the residue was chromatographed on silica gel (dichloromethane/methanol 19:1 and then dichloromethane/methanol 19:1 with 2% acetic acid) to yield 1180 mg (3.96 mmol) O-Benzoyl-5-hydroxybenzothiophene-2-carboxylic acid (2) as colorless crystals, mp. 235–236° C.

Workup

temperatureThe reaction mixture was warmed to room temperature
extractionThe aqueous phase was extracted twice with dichloromethane
customthe solvent of the organic phases was removed
customthe residue was chromatographed on silica gel (dichloromethane/methanol 19:1

Sources & evidence

ORD record: ord-9353f24c223b4af59958edf6334aa961
Source dataset: uspto-grants-2007_04
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US07208491B2

Reaction notes

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