Hydrochloric Acid → 6,6-Dimethyl-4-oxo-4,5,6,7-tetrahydro-benzofuran-3-carboxylic acid

HRID 1804774Notes

Reaction equation

[CH3:1][C:2]1([CH3:10])[CH2:7][C:6](=[O:8])[CH2:5][C:4](=[O:9])[CH2:3]1.[OH-].[K+].C([O:15][C:16](=[O:21])[C:17](=O)[CH2:18]Br)C.[OH-].[Na+].Cl>CO>[CH3:1][C:2]1([CH3:10])[CH2:3][C:4](=[O:9])[C:5]2[C:17]([C:16]([OH:21])=[O:15])=[CH:18][O:8][C:6]=2[CH2:7]1

Participants

Conditions

Temperature: 0 °C

Procedure

5,5-Dimethyl-1,3-cyclohexandione is dissolved in 15 ml of methanol and cooled to 0° C. A solution of KOH (2 g, 35.7 mmol) in 15 ml of methanol is added drop wise. A solution of 3-bromo-2-oxo-propionic acid ethyl ester (4.7 ml, 37.5 mmol) in 15 ml of methanol is added drop wise. The mixture is allowed to warm up to room temperature and is stirred for 16 h. Then 15 ml of a 45% aqueous sodium hydroxide solution is added. After additional 4 h at room temperature, 25 ml of concentrated HCl is added. Methanol is evaporated slowly under reduced pressure whereas the product precipitates as light crystals. The product is filtrated off and washed with water.

Workup

temperatureto warm up to room temperature
waitAfter additional 4 h at room temperature
customMethanol is evaporated slowly under reduced pressure whereas the product
customprecipitates as light crystals
filtrationThe product is filtrated off
washwashed with water

Sources & evidence

ORD record: ord-6a11854d0c904a019d3f55b5b15f4eaa
Source dataset: uspto-grants-2013_01
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US08354431B2

Reaction notes

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