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ChemicalBook CAS DataBase List tert-Butyl2-chloro-4-fluoroBenzoate
911314-43-7

tert-Butyl2-chloro-4-fluoroBenzoate synthesis

3synthesis methods
-

Yield:911314-43-7 71 %

Reaction Conditions:

Stage #1: tert-butyl alcoholwith n-butyllithium in tetrahydrofuran at 0;Inert atmosphere;
Stage #2: 2-chloro-4-fluorobenzoyl chloride in tetrahydrofuran at 0;Inert atmosphere;

Steps:

19.19b

Step 19b: Preparation of tert-butyl 2-chloro-4-fluorobenzoate (Compound 0102-28): To 2-chloro-4-fluorobenzoic acid (2.0 g, 11.46 mmol, 1.0 equiv)To a mixture of N,N-dimethylformamide (2 drops) in dichloromethane (20 mL) was added oxalyl chloride (1.94 mL, 22.91 mmol, 2.0 equiv).The mixture was stirred at room temperature for 4 hours. The solvent was removed under reduced pressure,and the residue was dissolved in tetrahydrofuran (5 mL) to obtain2-Chloro-4-fluorobenzoyl chloride solution. At 0°C under a nitrogen atmosphere,To a mixture of tert-butanol (1.32 mL, 13.75 mmol, 1.2 eq) in THF (15 mL) was added n-butyllithium (2.5M in hexane, 5.04 mL, 12.61 mmol, 1.1 eq) dropwise. The mixture was stirred for 10 minutes.A tetrahydrofuran solution of 2-chloro-4-fluorobenzoyl chloride was added dropwise,The mixture was then stirred at 0 °C for 1 hour. The reaction was quenched by adding saturated ammonium chloride solution (30 mL). The aqueous layer was extracted with ethyl acetate (20 mL×3). The combined organic layers were washed with saturated brine (20 mL×1),Dried over anhydrous sodium sulfate and concentrated. The residue was subjected to column chromatography on silica gel (petroleum ether: ethyl acetate 50:1) to obtain pale yellow oiltert-butyl 2-chloro-4-fluorobenzoate (1.88 g, yield: 71%).

References:

WO2022/213932,2022,A1 Location in patent:Page/Page column 62-63

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