Carbon Dioxide → 5-Methoxythiophene-2-carboxylic acid
Reaction equation
[CH3:1][O:2][C:3]1[S:4][CH:5]=[CH:6][CH:7]=1.[Li]CCCC.[C:13](=[O:15])=[O:14]>O1CCCC1>[CH3:1][O:2][C:3]1[S:4][C:5]([C:13]([OH:15])=[O:14])=[CH:6][CH:7]=1Participants
5
Reactant 3
Product 1
Reagents, catalysts & solvents 1
Procedure
2-(methyloxy)thiophene (1.01 g, 8.85 mmol) was added slowly over 15 min to a 100 mL round-bottomed flask containing 2.5M nBuLi in hexanes (3.8 mL, 9.50 mmol) in Tetrahydrofuran (THF) (40 mL) at −78° C. After warming to room temperature and stirring for 2 h, the mixture was cooled to −35° C. and crushed solid CO2 was added. The mixture warmed to room temperature over 3 hours and was cooled in an ice bath and quenched with NH4Cl(sat.). The cold reaction mixture was partitioned between CHCl3/H2O, the aqueous layer was made acidic with 6N HCl. The separated organic layer was dried with Na2SO4 and concentrated affording the title compound (1.3 g, 8.05 mmol, 91%) which was used without further purification: LC-MS (ES) m/z=159 (M+H)+.
Workup
- temperaturethe mixture was cooled to −35° C.
- additionwas added
- temperatureThe mixture warmed to room temperature over 3 hours
- temperaturewas cooled in an ice bath
- customquenched with NH4Cl(sat.)
- customThe cold reaction mixture
- customwas partitioned between CHCl3/H2O
- dry with materialThe separated organic layer was dried with Na2SO4
- concentrationconcentrated
Sources & evidence
- ORD record
- ord-d2e9ebf6f3d346d8b3155c32a18d6742
- Source dataset
- uspto-grants-2013_04
- Patent number
- US08410158B2
Reaction notes
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