反应详情

A mixture of methyl 3-[(dipropylamino)carbonyl]-5-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)benzoate (Step 1, 534 mg, 1.4 mmol), 4-bromobenzenedimethyl-sulfonamide (363 mg, 1.4 mmol), and sodium carbonate (2 mL of a 2 M mixture in water, 4.1 mmol) in toluene (10 mL) is degassed under reduced pressure for 15 minutes and then purged with argon. Palladium tetrakis(triphenylphosphine) (40 mg, 0.025 mmol) is added and the reaction mixture is degassed under reduced pressure for 15 minutes and then purged with argon. The reaction mixture is heated at reflux for 4 hours, cooled to 20–25 degrees C., filtered through a plug of diatomaceous earth and sodium sulfate, and the filtrate is concentrated under reduced pressure. Purification by flash column chromatography (silica; ethyl acetate/hexanes, 1/1) gives methyl 4′-[(dimethylamino)sulfonyl]-5-[(dipropylamino)carbonyl][1,1′-biphenyl]-3-carboxylate (XXXVIII), ESI-MS (m/z) [M+H]+=447.

1. customis degassed under reduced pressure for 15 minutes
2. custompurged with argon
3. customthe reaction mixture is degassed under reduced pressure for 15 minutes
4. custompurged with argon
5. temperatureThe reaction mixture is heated
6. temperatureat reflux for 4 hours
7. temperaturecooled to 20–25 degrees C
8. filtration, filtered through a plug of diatomaceous earth and sodium sulfate
9. concentrationthe filtrate is concentrated under reduced pressure
10. customPurification by flash column chromatography (silica; ethyl acetate/hexanes, 1/1)