Ethylene Glycol → 5-[1,3]Dioxolan-2-ylmethyl-pyrazine-2-carboxylic acid methyl ester
Reaction equation
[CH3:1][O:2][C:3]([C:5]1[CH:10]=[N:9][C:8]([CH2:11][CH:12]=[O:13])=[CH:7][N:6]=1)=[O:4].[CH2:14](O)[CH2:15][OH:16].O.C1(C)C=CC(S(O)(=O)=O)=CC=1>C1C=CC=CC=1>[CH3:1][O:2][C:3]([C:5]1[CH:10]=[N:9][C:8]([CH2:11][CH:12]2[O:16][CH2:15][CH2:14][O:13]2)=[CH:7][N:6]=1)=[O:4]Participants
Procedure
A solution of 5-(2-oxo-ethyl)-pyrazine-2-carboxylic acid methyl ester (295 mg, 1.42 mmol) and ethylene glycol (100 μL, 1.79 mmol) in benzene (10 mL) was treated with p-toluenesulfonic acid monohydrate (27 mg, 0.142 mmol), and the mixture was heated under reflux with a Dean-Stark condenser for 20 h. The mixture was cooled, diluted with benzene (15 mL), and then washed with a saturated aqueous sodium bicarbonate solution (10 mL) followed by a saturated aqueous sodium chloride solution (10 mL). Each aqueous phase was extracted with a small portion of benzene. The combined organic extracts were dried over sodium sulfate, filtered, and concentrated in vacuo to dryness to afford 5-[1,3]dioxolan-2-ylmethyl-pyrazine-2-carboxylic acid methyl ester as an orange oil (273 mg, 86%).
Workup
- temperaturethe mixture was heated
- temperatureunder reflux with a Dean-Stark condenser for 20 h
- temperatureThe mixture was cooled
- washwashed with a saturated aqueous sodium bicarbonate solution (10 mL)
- extractionEach aqueous phase was extracted with a small portion of benzene
- dry with materialThe combined organic extracts were dried over sodium sulfate
- filtrationfiltered
- concentrationconcentrated in vacuo to dryness
Sources & evidence
- ORD record
- ord-adfe9f21c77d4d9eab4aa66a0e5f0a4b
- Source dataset
- uspto-grants-2006_11
- Patent number
- US07132425B2
Reaction notes
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