N-octylpyridinium bromide synthesis

Yield:2534-66-9 79%

Reaction Conditions:

at 80; for 3 h;Inert atmosphere;

Steps:

Synthesis in a stirred reactor

ILs were synthesized by direct alkylation of pyridine with an equimolar amount of the corresponding bromoalkane in a round-bottomed flask (with diameter of 5.4 cm and total volume of 60 mL) equipped with a reflux condenser, a magnetic stirrer (250 rpm) and heated in an oil bath. The mixture was stirred at 80°C during a certain time (3h to 17h) under N₂ atmosphere, and during the reaction, a second, lower phase containing the ionic liquid appears. The reaction mixture was then cooled to room temperature. Specifications of syntheses for each bromoalkane are indicated below.n-butylpyridinium bromide. (Heating for 3h). After the excess of reagents was removed under reduced pressure, the obtained solid pyridinium was washed with ether and dried to give 17.3g of the desired salt [BuPy][Br] that corresponds to a chemical yield of 80%. n-hexylpyridinium bromide. (Heating for 3h). After cooling, the white precipitate formed into c.a. 350 mL diethylether was filtered, washed, dried and led to 21.2 g of the [HePy][Br] IL; chemical yield: 87%. n-octylpyridinium bromide. (Heating for 3h). 21.4g of [OcPy][Br] as a slightly brownish liquid (chemical yield: 79%) was obtained.

References:

Iken, Hicham;Guillen, Frédéric;Chaumat, Hélène;Mazières, Marie-Rose;Plaquevent, Jean-Christophe;Tzedakis, Théodore [Tetrahedron Letters,2012,vol. 53,# 27,p. 3474 - 3477] Location in patent:supporting information; experimental part