These common heterocyclic compound, 426-65-3, name is Ethyl Pentafluoropropionate, its traditional synthetic route has been very mature, but the traditional synthetic route has various shortcomings, such as complicated route, low yield, poor purity, etc, below Introduce a new synthetic route. 426-65-3
General procedure: Sodium hydride (4.0 g, 100 mmol, 60% dispersion in mineral oil) was placed in a 500mL round-bottom flack and 50 mL of dry hexane was added. The suspension was stirred for a short time with a magnetic stirring bar and kept until the hexane layer became clear (20-30 min). Hexane was cautiously removed with a glass pipette until a wet paste of NaH remained. This procedure was repeated twice. After that, THF (150mL) was added with vigorous stirring. Anhydrous EtOH (0.5 mL) was added in oneportion at 0 C, followed by the dropwise addition of a solution of 2-acetylthiophene (6.3g, 50 mmol, 5.42 mL) and methyl or ethyl ester of the respective perfluorinatedcarboxylic acid (50.5 mmol) in 30 mL of THF. The white suspension rapidly turns pink and then reddish-brown. Caution Hydrogen evolved during the addition and notable effervescence was observed. The rate of addition was maintained to control the evolution of hydrogen; usually the addition takes 60-80 min. When gas evolution ceased, the cooling bath was removed and the reaction mixture was stirred for 5 h. After that, the dark brown solution with a small amount of precipitate was re-cooled to 0 C,10 mL of anhydrous EtOH was added slowly to decompose traces of NaH, and the resulting solution was stirred for 30 min. The solvent was removed by evaporation under reduced pressure (100 Torr, bath temperature 40 C), then EtOAc (40 mL) andsubsequently a mixture of conc. HCl (20 mL) and crushed ice (80 mL) were added tothe residue. The resulting turbid liquid was shaken by hand until two clear layers formed. The organic phase was separated and the aqueous phase was then extracted with EtOAc (3 ¡Á 50 mL). The combined organic fractions were washed with brine (50mL), dried over MgSO4 and evaporated to dryness. The resulting brown oil was distilled in vacuo (2-3 Torr). The main fraction is pure enough. Additional portions of pure diketone can be separated from low-boiling fractions by precipitation as a copper salt. Decomposition should be performed with HCl (procedure A).
Chemical properties determine the actual use. Each compound has specific chemical properties and uses. We look forward to more synthetic routes in the future to expand reaction routes of 426-65-3.
Reference:
Article; Taydakov, Ilya V.; Kreshchenova, Yuliya M.; Dolotova, Ekaterina P.; Beilstein Journal of Organic Chemistry; vol. 14; (2018); p. 3106 – 3111;,
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