Lithium Carbonate → Methyl 4-hydroxybenzo[b]thiophene-5-carboxylate

HRID 411194Notes

Reaction equation

Br[C:2]1([C:12]([O:14][CH3:15])=[O:13])[C:10](=[O:11])[C:6]2[CH:7]=[CH:8][S:9][C:5]=2[CH2:4][CH2:3]1.C(=O)([O-])[O-].[Li+].[Li+]>CN(C=O)C>[OH:11][C:10]1[C:6]2[CH:7]=[CH:8][S:9][C:5]=2[CH:4]=[CH:3][C:2]=1[C:12]([O:14][CH3:15])=[O:13]

Participants

Conditions

Temperature: 100 °C

Procedure

A solution containing methyl 5-bromo4-oxo-4,5,6,7-tetrahydro-1-benzothiophene-5-carboxylate (Preparation 12, 1.18 g) and lithium carbonate (1.81 g) in anhydrous DMF (10 mL) is heated at 100° C. overnight. After cooling, the solids are removed by filtration and the filtrate is partitioned between ethyl acetate (50 mL) and water (50 mL). The organic layer is washed with brine, dried over Na2SO4, filtered, and concentrated to give a brown solid. This crude product is chromatographed on a Biotage column eluting with 0-20% ethyl acetate in heptane (250 mL each 10%) to give 270 mg (32%) of the title compound as a white solid. Physical characteristics: Mp 94-95° C.; MS (ESI−) m/z 207.0 (M−H)−. Anal. found: C, 57.26; H, 3.88; N, 0.17.

Workup

temperatureAfter cooling
customthe solids are removed by filtration
customthe filtrate is partitioned between ethyl acetate (50 mL) and water (50 mL)
washThe organic layer is washed with brine
dry with materialdried over Na2SO4
filtrationfiltered
concentrationconcentrated
customto give a brown solid
customThis crude product is chromatographed on a Biotage column
washeluting with 0-20% ethyl acetate in heptane (250 mL each 10%)

Sources & evidence

ORD record: ord-9048297e026e46ee9af2688d2d4482ef
Source dataset: uspto-grants-2003_05
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US06559145B2

Reaction notes

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