2-(4-Bromophenyl)-1,3-dioxolane → 1-[4-(1,3-Dioxolan-2-yl)phenyl]-2-(2-thienyl)ethanone

Temperature

-78 °C

A 25 ml RB flask with a stirring bar was charged with 1-bromo-4-(1,3-dioxolan-2-yl)benzene (243 mg, 1.0 mmol), followed by anhydrous THF (5 mL). The mixture was cooled to −78° C. and n-butyllithium (687 μL of 1.6 M solution in hexanes) was added dropwise over 2 min. After stirring for 15 min. at −78° C., N-methoxy-N-methyl-2-(2-thienyl)acetamide (1-1) (185 mg, 1 mmol) was added in one portion. After another 30 min at −78° C., the mixture was quenched with sat. ammonium chloride (20 mL), extracted twice with ethyl acetate (10 mL). The combined organic extracts were dried over sodium sulfate, concentrated, and purified via column chromatography over silica gel (0-50% ethyl acetate/hexanes) to give 1-[4-(1,3-dioxolan-2-yl)phenyl]-2-92-thienyl)ethanone (1-2). 1H NMR (CDCl3, ppm) δ: 7.98 (d, J=8.25 Hz, 2H), 7.45 (d, J=8.25 Hz, 2H), 7.15 (d, J=5.15 Hz, 1H), 6.86 (m, 1H), 6.83 (m, 1H), 5.77 (s, 1H), 4.38 (s, 2H), 4.01 (m, 4H).

1. waitAfter another 30 min at −78° C.
2. customthe mixture was quenched with sat. ammonium chloride (20 mL)
3. extractionextracted twice with ethyl acetate (10 mL)
4. dry with materialThe combined organic extracts were dried over sodium sulfate
5. concentrationconcentrated
6. custompurified via column chromatography over silica gel (0-50% ethyl acetate/hexanes)

ORD record

ord-26b3bcda0ec843db9497968afdf2207e

Source dataset

uspto-grants-2009_09

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07589068B2