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ChemicalBook CAS DataBase List Pyrimidine-5-carboxaldehyde
10070-92-5

Pyrimidine-5-carboxaldehyde synthesis

7synthesis methods
Under nitrogen, a solution of 5-bromopyrimidine (1 g, 6.3 mmol) in 60 mL anhydrous THF was added BuLi (2.5 M, 2.6 mL, 6.5 mmol) at -78° C. The resulting yellow solution was stirred for 20 min, after which ethyl formate (0.55 mL, 6.7 mmol) was added dropwise over 5 min. After 20 min, the reaction was quenched with 1.5 M THF/HCl solution (4.5 mL, 6.7 mmol). The cold bath was removed, and the reaction mixture was stirred for 1 h. THF was removed in vacco, 10 mL of water was then added. The mixture was extracted with CHCl3 (2*10 mL), and the combined organics were dried (MgSO4) and concentrated. The crude product was purified via flash column chromatography (5 per cent MeOH/CHCl3) to give 0.35 g (51 per cent) of the titled Pyrimidine-5-carboxaldehyde.
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Yield:10070-92-5 35%

Reaction Conditions:

with hydrogenchloride;n-butyllithium in tetrahydrofuran;hexane;water

Steps:

15.1 1)
1) Preparation of pyrimidine-5-carbaldehyde A solution of 5-bromo-pyrimidine (5 g, 31.4 mmol, 1.0 eq.) in anhydrous THF (300 mL) was placed under an argon atmosphere in a three-necked round bottom flask equipped with a low-temperature thermometer. The mixture was cooled to -100°C in a EtOH/N2(1) bath. To the solution of 5-bromopyridine was added a solution of n-BuLi in hexane (20 mL, 1.6 M, 32.5 mmol, 1.0 eq.). The resulting mixture was stirred for 20 minutes at 100°C and the organolithium that formed was trapped with a solution of ethyl formate (2.7 mL, 33.5 mmol, 1.1 eq.) in THF (10 mL). The reaction was stirred for another 20 minutes at 100°C and quenched with a solution of hydrochloric acid in ether (17 mL, 2M, 34 mmol). Then, the cold bath was removed and the mixture stirred at room temperature for 1 hour. The solution was concentrated under reduced pressure, and then treated with water and saturated aqueous sodium carbonate (10 mL). The mixture was extracted with dichloromethane and the organic layer was dried over MgSO4. The solvent was removed under reduced pressure and the residue purified by silica gel flash-column chromatography (eluent: CH2Cl2/AcOEt, 60:40 to 50:50) to afford pyrimidine-5-carbaldehyde as beige crystals (1.2 g, 35%).

References:

Centre National de la Recherche Scientifique EP2266562, 2010, A1

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