Reacción #446340

Ecuación de reacción

pyridine

hexadecyl-4-hydroxypyridinium chloride

pyridine

ethanol

→

Dodecylpyridinium chloride

Rendimiento 70.0%

Disolventes

methanol

bromide

ether ethanol

methanol

Condiciones de reacción

Tratamiento posterior

1. 1
   Otrowhich must be subsequently preparatively purified by high-pressure liquid chromatography (HPLC)
2. 2
   workup.DISSOLUTIONare firstly dissolved in methanol (10 times excess volume with respect to pyridine) and under nitrogen the stoichiometric amount of pyridine
3. 3
   workup.DISSOLUTIONalso dissolved
4. 4
   workup.ADDITIONn methanol, added dropwise
5. 5
   TemperaturaHeating
6. 6
   Temperaturaunder reflux
7. 7
   workup.STIRRINGwhilst stirring at 70° C. so that the reaction
8. 8
   Otroyield

Procedimiento

The corresponding compounds of pyridine or substituted pyridine, as six-member heterocycle, can be prepared from the corresponding alkyl bromides or iodides in methanol at 35° C. and pyridine or substituted pyridines with a yield of 70%. The corresponding molar amounts of the alkyl bromide, almost all of which are available commercially but which must be subsequently preparatively purified by high-pressure liquid chromatography (HPLC), are firstly dissolved in methanol (10 times excess volume with respect to pyridine) and under nitrogen the stoichiometric amount of pyridine, also dissolved :n methanol, added dropwise whilst stirring. Heating is carried out for 6 hours under reflux whilst stirring at 70° C. so that the reaction yield is almost quantitative. Thus, for example, the yield of hexadecyl-4-hydroxypyridinium chloride or bromide in methanol as solvent is 95%, with ethanol 80% and in ether/ethanol only 40%. Dodecylpyridinium chloride is obtained with a yield of almost 70%. 3,5-dihydroxydodecylpyridinium bromide is formed quantitatively in accordance with the above procedure from dodecyl bromide and 3,5-dihydroxypyridine in boiling chloroform after 4 hours (melting point 180° C.).

Fuente