tert-Butyldimethylsilyl chloride → 2-(tert-Butyldimethylsilyl)-N,N-dimethyl-1H-imidazole-1-sulfonamide

HRID 560045Notes

Reaction equation

HRID 560045 reaction equation
[CH3:1][N:2]([CH3:11])[S:3]([N:6]1[CH:10]=[CH:9][N:8]=[CH:7]1)(=[O:5])=[O:4].[Li]CCCC.[Si:17](Cl)([C:20]([CH3:23])([CH3:22])[CH3:21])([CH3:19])[CH3:18]>C1COCC1.O>[CH3:1][N:2]([CH3:11])[S:3]([N:6]1[CH:10]=[CH:9][N:8]=[C:7]1[Si:17]([C:20]([CH3:23])([CH3:22])[CH3:21])([CH3:19])[CH3:18])(=[O:4])=[O:5]

Participants

6

Reactant 3

HCID 28928tert-Butyldimethylsilyl chlorideHCID 395751N,N-Dimethyl-1H-imidazole-1-sulfonamideHCID 178418339Butyllithium

Product 1

HCID 64202092-(tert-Butyldimethylsilyl)-N,N-dimethyl-1H-imidazole-1-sulfonamide

Reagents, catalysts & solvents 2

HCID 962WaterSolventHCID 8028TetrahydrofuranSolvent2×

Conditions

Temperature
-78 °C

Procedure

Imidazole (Intermediate L1, available from Aldrich, 20.0 g, 0.29 mol), triethylamine (41.0 mL, 0.29 mol) and N,N-dimethylsulfamoyl chloride (31.6 mL, 0.29 mol) were added to benzene (320 mL). The reaction was stirred for 48 h at rt and then filtered. The filtrate was collected and concentrated under reduced pressure. Vacuum distillation of the crude produce (˜0.5 mmHg, 115-118° C.) afforded dimethylsulfamoyl) imidazole (Intermediate L2) 38.7 g (76%) as a clear and colorless oil. Upon cooling the product solidifies to give white crystals. 1-(Dimethylsulfamoyl) imidazole (Intermediate L2) (18.8 g, 0.11 mol) was added to THF (430 mL). The solution was cooled to −78° C. A solution of n-BuLi (70.9 mL, 1.6 M in hexane) was added dropwise to the reaction mixture. Upon completion, the solution was stirred for 1 h at −78° C. t-Butyldimethylsilylchloride (TBSCl) (17.8 g, 0.12 mol) in THF (50 mL) was added via cannula to the mixture. After the addition was completed the reaction mixture was warmed slowly to rt and stirred for 24 h. The mixture was diluted with water and the organic layer separated. The organic phase was washed with brine and then dried over Na2SO4. The mixture was filtered and the filtrate concentrated under reduced pressure. Column chromatography on SiO2 with 20% ethyl acetate/hexane afforded 1-dimethylsulfamoyl-2-t-butyldimethylsilyl imidazole (Formula 13) as a light yellow solid. Recrystallization from pentane gave 30 g (94%) of white crystals.

Workup

  1. temperatureUpon cooling the product
  2. customto give white crystals
  3. additionwas added via cannula to the mixture
  4. additionAfter the addition
  5. temperaturewas warmed slowly to rt
  6. customthe organic layer separated
  7. washThe organic phase was washed with brine
  8. dry with materialdried over Na2SO4
  9. filtrationThe mixture was filtered
  10. concentrationthe filtrate concentrated under reduced pressure

Sources & evidence

ORD record
ord-1cd0436a7441433fa04e05b32a939dcd
Source dataset
uspto-grants-2011_11
Patent number
US08063087B2

Reaction notes

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