ChemicalBook CAS DataBase List Ethyl 2,2-Difluoropropionate

Ethyl 2,2-Difluoropropionate synthesis

6synthesis methods

Product Name:Ethyl 2,2-Difluoropropionate
CAS Number:28781-85-3
Molecular formula:C5H8F2O2
Molecular Weight:138.11

617-35-6
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28781-85-3
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$15.00/1g

Yield:28781-85-3 99.4%

Reaction Conditions:

with (bis-(2-methoxyethyl)amino)sulfur trufluoride at -15 - 30;

Steps:

Preparation of Starting material 2-(2,2-Difluoropropylamino)-ethanol (Sm-1c) Two 22 liter 3-neck round-bottomed flasks equipped with a mechanical stirrer, thermometer, nitrogen inlet and drying tubes were each charged with ethyl pyruvate (2350 g, 20.24 mol) and then cooled to -15 to -10° C. using a dry ice/acetone bath. [Bis(2-methoxyethyl)amino]sulfur trifluoride (DeoxoFluor; 3731 ml, 20.24 mol) was then added to each of the flasks while maintaining the temperature less than -5° C. The reaction mixtures were then stirred at a temperature less than 30° C. until no more starting material was present by gas chromatography (GC). Each reaction mixture was then added to a stirred mixture of water (16.6 Kg)/ice(16.6 Kg) and sodium bicarbonate (3.3 Kg) in a 30 gallon crock over approximately 30 minutes. The aqueous mixtures were then stirred overnight to room temperature. The two layers were separated for each crude reaction mixture and the aqueous layers were split in half and each extracted with methylene chloride (3* 2 liters). The methylene chloride layers were combined (24 L total) and then washed with brine (1* 2 liters) followed by treatment with charcoal and dried over magnesium sulfate. The solvent was removed and the liquid residue distilled at 60-110° C. at atmospheric pressure to yield 5557 g (99.4%) of 2,2-difluoro-propionic acid ethyl ester.

References:

US2007/260056,2007,A1 Location in patent:Page/Page column 13

64-17-5 Synthesis