1-Bromododecane → 1-Bromododecane

HRID 1085895Notes

Reaction equation

HRID 1085895 reaction equation
[CH3:1][C:2]1[NH:3][CH:4]=[CH:5][N:6]=1.[OH-].[K+].[Br:9][CH2:10][CH2:11][CH2:12][CH2:13][CH2:14][CH2:15][CH2:16][CH2:17][CH2:18][CH2:19][CH2:20][CH3:21]>C1(C)C=CC=CC=1>[CH2:21]([N:3]1[CH:4]=[CH:5][N:6]=[C:2]1[CH3:1])[CH2:20][CH2:19][CH2:18][CH2:17][CH2:16][CH2:15][CH2:14][CH2:13][CH2:12][CH2:11][CH3:10].[Br:9][CH2:10][CH2:11][CH2:12][CH2:13][CH2:14][CH2:15][CH2:16][CH2:17][CH2:18][CH2:19][CH2:20][CH3:21]

Participants

6

Reactant 3

HCID 89191-Bromododecane2×HCID 127492-MethylimidazoleHCID 14797Potassium Hydroxide

Product 2

HCID 89191-BromododecaneHCID 150999061-Dodecyl-2-methyl-1H-imidazole

Reagents, catalysts & solvents 1

HCID 1140TolueneSolvent

Conditions

Temperature
60 °C

Procedure

After the reaction is completed, the reaction mixture contains a solution comprised of the 1-alkylimidazole and inorganic materials dissolved in the non-reactive aromatic solvent. The dissolved inorganic materials are unreacted base and inorganic salts which would be expected to form in the alkylation reaction. In addition, substantial amounts of insoluble unreacted base and inorganic salt are dispersed in the solution. For example, if imidazole is alkylated with 1-bromobutane in the presence of potassium hydroxide in toluene, the product mixture would contain a 1-butylimidazole-toluene solution in which are dissolved small amounts of potassium bromide and unreacted potassium hydroxide and undissolved potassium bromide and potassium hydroxide dispersed in the 1-butylimidazole-toluene solution. The solid inorganic material can be separated from the toluene solution by any means known to those skilled in the art such as by filtration. Inorganic material as defined above dissolved in the toluene solution can be removed by any means known to those skilled art such as by washing the organic phase with aqueous brine solutions. The imidazole product may be isolated from the solvent or may remain dissolved therein. The product imidazole can be isolated by any means known to those skilled in the art such as by distillation of the solvent. In a preferred embodiment of the present invention, about 1.5 moles of 2-methylimidazole and about 1.9 moles of potassium hydroxide powder are mixed with about 536 mL of toluene and heated to about 60° C. for 30 minutes with stirring. The temperature is then raised to 90° C. and about 1.36 moles of 1-bromododecane are added over 60 minutes. After the addition is complete, the reaction mixture is then maintained at 90° C. until the 1-bromododecane is no longer observable by GC analysis of the reaction mixture. The reaction mixture is then cooled and the organic phase and inorganic phases separated by filtration. The organic phase is washed with four 500 mL portions of brine and the toluene is removed at 40° C. under vacuum leaving a 99 mole % yield of N-dodecyl-2-methylimidazole relative to 1-bromododecane.

Workup

  1. distillationsuch as by distillation of the solvent
  2. temperatureThe temperature is then raised to 90° C.
  3. additionAfter the addition
  4. temperatureThe reaction mixture is then cooled
  5. customthe organic phase and inorganic phases separated by filtration
  6. washThe organic phase is washed with four 500 mL portions of brine
  7. customthe toluene is removed at 40° C. under vacuum

Sources & evidence

ORD record
ord-c361846f97904359a567190fbebe81b4
Source dataset
uspto-grants-1991_04
Patent number
US05011934

Reaction notes

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