Ethylene Glycol → 2-(3-Thienyl)-1,3-dioxolane

Temperature

0 °C

To a solution of thiophene-3-carbaldehyde (25.00 g, 222.9 mmol) in toluene (250 ml) were added ethylene glycol (69.18 g, 1115 mmol) and p-toluenesulfonic acid (424.0 mg, 2.229 mmol). The mixture was heated under reflux for 4 hr while separating generated water using Dean-Stark trap. After cooling to 0° C., saturated aqueous sodium hydrogen carbonate solution (50 ml) was added, and the mixture was stirred, stood still and then partitioned. The aqueous layer was extracted twice with ethyl acetate. The combined organic layer was washed with water and saturated brine, and dried over anhydrous magnesium sulfate. The residue was concentrated under reduced pressure, filtered through silica gel pad (FUJI SILYSIA CHEMICAL LTD. BW-300SP 100 g), and washed with ethyl acetate/hexane mixed solvent (1:2, 1000 ml). The filtrate was concentrated under reduced pressure to give 2-(thiophen-3-yl)-1,3-dioxolane (33.40 g, 213.8 mmol, yield 95.9%) as a yellow oil.

1. temperatureThe mixture was heated
2. temperatureunder reflux for 4 hr
3. customwhile separating
4. additionsaturated aqueous sodium hydrogen carbonate solution (50 ml) was added
5. custompartitioned
6. extractionThe aqueous layer was extracted twice with ethyl acetate
7. washThe combined organic layer was washed with water and saturated brine
8. dry with materialdried over anhydrous magnesium sulfate
9. concentrationThe residue was concentrated under reduced pressure
10. filtrationfiltered through silica gel pad (FUJI SILYSIA CHEMICAL LTD. BW-300SP 100 g)
11. washwashed with ethyl acetate/hexane mixed solvent (1:2, 1000 ml)
12. concentrationThe filtrate was concentrated under reduced pressure

ORD record

ord-ef573884615549a2bc5bca427d542e40

Source dataset

uspto-grants-2013_08

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08507690B2