Hydrochloric Acid → N-tert.-butyl-5-methyl-thiophene-2-sulfonamide

HRID 1388193Notes

Reaction equation

HRID 1388193 reaction equation
Cl[S:2]([OH:5])(=O)=[O:3].P(Cl)(Cl)(Cl)(Cl)Cl.Cl.[CH3:13][C:14]1[S:15][CH:16]=[CH:17][CH:18]=1.[C:19]([NH2:23])([CH3:22])([CH3:21])[CH3:20]>O1CCCC1>[C:19]([NH:23][S:2]([C:16]1[S:15][C:14]([CH3:13])=[CH:18][CH:17]=1)(=[O:5])=[O:3])([CH3:22])([CH3:21])[CH3:20]

Participants

7

Reactant 5

HCID 313Hydrochloric AcidHCID 6385Tert-ButylamineHCID 111262-MethylthiopheneHCID 24638Chlorosulfonic acidHCID 24819Phosphorus pentachloride

Product 1

HCID 20471879N-tert.-butyl-5-methyl-thiophene-2-sulfonamideYield 78%

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent

Procedure

291 gm (2.5 mol) of chlorosulfonic acid were added in portions to 208 gm (1.0 mol) of phosphorus pentachloride while stirring and cooling. After the evolution of hydrogen chloride had subsided, 98 gm (1.0 mol) of 2-methyl-thiophene were added dropwise while stirring at a temperature of 10° C. When the addition was finished, the mixture was stirred for another 10 minutes. After pouring the reaction mixture over 2.5 kg of ice, the obtained sulfochloride was separated by extracting 5 times with 500 ml of ether. The organic phase was washed twice with 200 ml of water, dried and evaporated in vacuo. The residual oil was taken up in 200 ml of tetrahydrofuran and added, while stirring, dropwise, to a solution of 183 gm (2.5 mol) of tert. butylamine in 100 ml of tetrahydrofuran at a temperature of 20° C. The mixture was stirred for 1 hour at room temperature and for 20 minutes at 70° C. bath temperature. The crystals of tert. butylamine hydrochloride which separated out were filtered off and washed with ether. The combined filtrates were evaporated, and the residue was taken up in ether. After washing with 2 N hydrochloric acid and water, the residue was dried over sodium sulfate and again evaporated. The obtained crude product was recrystallized from cyclohexane, yielding 182 gm (78% of theory) of N-tert.-butyl-5-methyl-thiophene-2-sulfonamide.

Workup

  1. temperaturecooling
  2. stirringwhile stirring at a temperature of 10° C
  3. additionWhen the addition
  4. stirringthe mixture was stirred for another 10 minutes
  5. customthe obtained sulfochloride was separated
  6. extractionby extracting 5 times with 500 ml of ether
  7. washThe organic phase was washed twice with 200 ml of water
  8. customdried
  9. customevaporated in vacuo
  10. additionadded
  11. stirringwhile stirring
  12. customat a temperature of 20° C
  13. stirringThe mixture was stirred for 1 hour at room temperature and for 20 minutes at 70° C. bath temperature
  14. customThe crystals of tert. butylamine hydrochloride which separated out
  15. filtrationwere filtered off
  16. washwashed with ether
  17. customThe combined filtrates were evaporated
  18. washAfter washing with 2 N hydrochloric acid and water
  19. dry with materialthe residue was dried over sodium sulfate
  20. customagain evaporated
  21. customThe obtained crude product
  22. customwas recrystallized from cyclohexane

Sources & evidence

ORD record
ord-f72594687fa64f2ebc34831e764c3123
Source dataset
uspto-grants-1984_02
Patent number
US04430355

Reaction notes

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