Anisole → 2-bromo-N'-methylbenzenesulfonimidamide

HRID 247000Notes

Reaction equation

HRID 247000 reaction equation
[Br:1][C:2]1[CH:7]=[CH:6][CH:5]=[CH:4][C:3]=1[S:8](=[N:15]C)([NH:10][C:11](C)(C)C)=[O:9].B(F)(F)F.CCOCC.C1(OC)C=CC=CC=1.FC(F)(F)S(O)(=O)=O.C([O-])(=O)C.[Na+].C(=O)([O-])[O-].[K+].[K+]>FC(F)(F)C(O)=O.ClCCl.O>[Br:1][C:2]1[CH:7]=[CH:6][CH:5]=[CH:4][C:3]=1[S:8](=[N:10][CH3:11])([NH2:15])=[O:9]

Participants

10

Reactant 6

HCID 7519AnisoleHCID 8000Boron trifluoride etherateHCID 11430Potassium CarbonateHCID 62406Trifluoromethanesulfonic acidHCID 517045Sodium AcetateHCID 139208992-bromo-N-(1,1-dimethylethyl)-N'-methylbenzenesulfonimidamide2×

Product 1

HCID 139209002-bromo-N'-methylbenzenesulfonimidamide

Reagents, catalysts & solvents 3

HCID 962WaterSolventHCID 6344DichloromethaneSolventHCID 6422Trifluoroacetic acidSolvent2×

Procedure

Cleavage of the tert-butyl group from 2-bromo-N-(1,1-dimethylethyl)-N'-methylbenzenesulfonimidamide by use of trifluoroacetic acid with or without added boron trifluoride etherate was found to be slow at room temperature. 2-Bromo-N-(1,1-dimethylethyl)-N'-methylbenzenesulfonimidamide (0.9 g, 2.9 mmol) recovered from these cleavage experiments and anisole (0.6 g, 5.5 mmol) were dissolved in trifluoroacetic acid (25 mL). Trifluoromethanesulfonic acid (ca. 9 g, 60 mmol) was added and the reaction mixture was stirred at room temperature for 1 hour. Then sodium acetate (5.5 g, 67 mmol) was added and the solvent was evaporated to leave a solid residue. This was dissolved in a mixture of dichloromethane and a small amount of water. Potassium carbonate was added until the mixture became basic. The mixture was partially dried (Na2SO4), filtered through Celite®, redried (Na2SO4), and gravity filtered. Evaporation of the solvent left a slightly brownish oil (1.4 g). This was dissolved in dichloromethane and chromatographed on a column of silica gel using 40:1 CH2Cl2 --Et2O followed by 1:1 CH2Cl2 --Et2O as eluant. Fractions containing the product (Rf =0.44, 10:1 CH2Cl2 --Et2O, UV) were evaporated to leave 2-bromo-N'-methylbenzenesulfonimidamide as a colorless oil (0.7 g.).

Workup

  1. customto be slow at room temperature
  2. customthe solvent was evaporated
  3. customto leave a solid residue
  4. dry with materialThe mixture was partially dried (Na2SO4)
  5. filtrationfiltered through Celite®
  6. dry with materialredried (Na2SO4), and gravity
  7. filtrationfiltered
  8. customEvaporation of the solvent
  9. waitleft a slightly brownish oil (1.4 g)
  10. dissolutionThis was dissolved in dichloromethane
  11. customchromatographed on a column of silica gel using 40:1 CH2Cl2
  12. additionFractions containing the product (Rf =0.44, 10:1 CH2Cl2 --Et2O, UV)
  13. customwere evaporated

Sources & evidence

ORD record
ord-98f8b3c9f19b4ee68b9afb6fef7e7419
Source dataset
uspto-grants-1987_11
Patent number
US04705555

Reaction notes

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