Ethanol → Dodecylpyridinium chloride

HRID 729004Notes

Reaction equation

HRID 729004 reaction equation
N1C=CC=CC=1.C(O)C.[Cl-:10].[CH2:11]([N+:27]1[CH:32]=[CH:31][C:30](O)=[CH:29][CH:28]=1)[CH2:12][CH2:13][CH2:14][CH2:15][CH2:16][CH2:17][CH2:18][CH2:19][CH2:20][CH2:21][CH2:22]CCCC>CO.[Br-].CCOCC.C(O)C>[Cl-:10].[CH2:11]([N+:27]1[CH:28]=[CH:29][CH:30]=[CH:31][CH:32]=1)[CH2:12][CH2:13][CH2:14][CH2:15][CH2:16][CH2:17][CH2:18][CH2:19][CH2:20][CH2:21][CH3:22]

Participants

7

Reactant 3

HCID 702EthanolHCID 1049Pyridine2×HCID 19880264Hexadecyl-4-hydroxypyridinium chloride

Product 1

HCID 7717Dodecylpyridinium chlorideYield 70%

Reagents, catalysts & solvents 3

HCID 259Bromide ionSolventHCID 887MethanolSolvent2×HCID 21585056Diethyl ether ethanolSolvent

Procedure

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 in 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.).

Workup

  1. customwhich must be subsequently preparatively purified by high-pressure liquid chromatography (HPLC)
  2. dissolutionare firstly dissolved in methanol (10 times excess volume with respect to pyridine) and under nitrogen the stoichiometric amount of pyridine
  3. dissolutionalso dissolved in methanol
  4. additionadded dropwise
  5. temperatureHeating
  6. temperatureunder reflux
  7. stirringwhilst stirring at 70° C. so that the reaction
  8. customyield

Sources & evidence

ORD record
ord-d1d9fc6439ca4535b9b4d7f814f58294
Source dataset
uspto-grants-1991_09
Patent number
US05051435

Reaction notes

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