Reaktion #70563

Reaktionsgleichung

triphenylphosphine

sodium bicarbonate

tributyl(1-ethoxyvinyl)tin

hydrochloric acid

5-bromo-2-phenylpyrimidine

→

title intermediate

Ausbeute 33.8%

1-(2-phenylpyrimidin-5-yl)ethanone

Ausbeute 33.8%

Lösungsmittel

1,4-dioxane

1,4-dioxane

Reaktionsbedingungen

Aufarbeitung

1. 1
   SonstigeThe dark reaction mixture
2. 2
   Temperaturwas cooled to room temperature
3. 3
   workup.ADDITIONto this reaction mixture was added a solution
4. 4
   Temperaturheated at 75° C. overnight
5. 5
   Temperaturwas subsequently cooled to room temperature
6. 6
   ExtraktionThe organic material was extracted two times
7. 7
   workup.ADDITIONwith a mixture of ethyl acetate and hexanes
8. 8
   Waschenthe combined organic phase was washed sequentially with water and brine
9. 9
   Trocknenwas dried over anhydrous magnesium sulfate
10. 10
    Filtrationfiltered through a well packed pad of magnesium sulfate
11. 11
    Einengenconcentrated under reduced pressure
12. 12
    workup.DISSOLUTIONThe residue was dissolved in dichloromethane (30 mL)
13. 13
    workup.ADDITIONdiluted with hexanes (30 mL)
14. 14
    FiltrationThe resulting precipitate was filtered

Vorschrift

A stirring mixture consisting of palladium(II) acetate (215 mg, 0.32 mmol) and triphenylphosphine (335 mg, 1.28 mmol) in 1,4-dioxane (25 mL) was heated at 80° C. for 30 minutes. The dark reaction mixture was cooled to room temperature, and to this reaction mixture was added a solution consisting of 5-bromo-2-phenylpyrimidine (Example 1A, 3.0 g, 13 mmol) and tributyl(1-ethoxyvinyl)tin (4.74 mL, 14.0 mmol) in 1,4-dioxane (63 mL). The reaction mixture was stirred and heated at 75° C. overnight and was subsequently cooled to room temperature. The reaction progress was monitored by thin layer chromatography (95:5 v/v hexanes-ethyl acetate) until completion. The reaction mixture was treated with 1 N hydrochloric acid (19 mL) for one hour at room temperature and poured into a saturated aqueous sodium bicarbonate solution. The organic material was extracted two times with a mixture of ethyl acetate and hexanes, and the combined organic phase was washed sequentially with water and brine, and was dried over anhydrous magnesium sulfate, filtered through a well packed pad of magnesium sulfate, and concentrated under reduced pressure. The residue was dissolved in dichloromethane (30 mL) and diluted with hexanes (30 mL). The resulting precipitate was filtered to give the title intermediate (872 mg). The filtrate was applied to a 80-g silica column eluted with 1:1:9 v/v/v ethyl acetate-dichloromethane-hexanes to afford 1.01 g of additional title intermediate (1.88 g total, 74%); Rf 0.23 with 9:1 v/v hexanes-ethyl acetate solvent system; 1H-NMR (400 MHz; DMSO-d6) δ 9.4 (s, 2H), 8.45-8.50 (m, 2H), 7.5-7.7 (m, 3H), 2.68 (s, 3H); MS (ESI+) m/z 199 (M+1).

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