Chlorosulfonic acid → 2,2,5,7,8-pentamethylchroman-6-sulfonyl Chloride

HRID 1709041Notes

Reaction equation

HRID 1709041 reaction equation
[CH3:1][C:2]1([CH3:15])[CH2:11][CH2:10][C:9]2[C:4](=[C:5]([CH3:14])[C:6]([CH3:13])=[CH:7][C:8]=2[CH3:12])[O:3]1.[Cl:16][S:17](O)(=[O:19])=[O:18]>ClC(Cl)Cl>[S:17]([Cl:16])([C:7]1[C:6]([CH3:13])=[C:5]([CH3:14])[C:4]2[O:3][C:2]([CH3:15])([CH3:1])[CH2:11][CH2:10][C:9]=2[C:8]=1[CH3:12])(=[O:19])=[O:18]

Participants

4

Reactant 2

HCID 24638Chlorosulfonic acidHCID 17978072,2,5,7,8-Pentamethylchroman

Product 1

HCID 43744402,2,5,7,8-pentamethylchroman-6-sulfonyl ChlorideYield 39.7%

Reagents, catalysts & solvents 1

HCID 6212ChloroformSolvent

Conditions

Temperature
0 °C

Procedure

The starting material for this synthesis was 2,2,5,7,8-pentamethylchroman and 77.55 g, 0.38 mol was dissolved in trichloromethane (1 liter) and cooled to 0° C. Chlorosulphonic acid (176.85 g, 1.52 mol) in a further 800 ml of solvent was added and the mixture stirred for 15 minutes at 0° C. and then for a further hour without cooling. The reaction mixture was poured onto ice and the organic layer separated off. This organic layer was then washed with 5% sodium carbonate solution, with saturated sodium bicarbonate solution and with brine. The aqueous washings were combined and extracted with more solvent. The original organic layer and the organic extract were combined, dried over anhydrous magnesium sulphate, stirred with activated charcoal and filtered through kieselguhr. Most of the trichloromethane was removed in vacuuo and then petroleum ether (40/60° C.) was added and the remainder of the trichloromethane was removed in vacuo. This crude product was dissolved in more petroleum ether and the solution cooled to 0° C. and filtered to give 45.96 g of Pmc-Cl (yield 39.7%, melting point 77-82° C.).

Workup

  1. temperaturefor a further hour without cooling
  2. additionThe reaction mixture was poured onto ice
  3. customthe organic layer separated off
  4. washThis organic layer was then washed with 5% sodium carbonate solution, with saturated sodium bicarbonate solution and with brine
  5. extractionextracted with more solvent
  6. extractionThe original organic layer and the organic extract
  7. dry with materialdried over anhydrous magnesium sulphate
  8. stirringstirred with activated charcoal
  9. filtrationfiltered through kieselguhr
  10. customMost of the trichloromethane was removed in vacuuo
  11. additionpetroleum ether (40/60° C.) was added
  12. customthe remainder of the trichloromethane was removed in vacuo
  13. dissolutionThis crude product was dissolved in more petroleum ether
  14. temperaturethe solution cooled to 0° C.
  15. filtrationfiltered

Sources & evidence

ORD record
ord-f006a73183aa4f55ba8e21a988834af8
Source dataset
uspto-grants-1990_08
Patent number
US04946971

Reaction notes

Loading…