Sulfuric Acid → 2,2,4,4-Tetramethyl-6-bromothiochroman

HRID 52374Notes

Reaction equation

HRID 52374 reaction equation
[Br:1][C:2]1[CH:7]=[CH:6][C:5]([SH:8])=[C:4]([C:9]([CH3:16])([CH3:15])[CH2:10][C:11]([CH3:14])(O)[CH3:12])[CH:3]=1.OS(O)(=O)=O>>[CH3:12][C:11]1([CH3:14])[CH2:10][C:9]([CH3:16])([CH3:15])[C:4]2[C:5](=[CH:6][CH:7]=[C:2]([Br:1])[CH:3]=2)[S:8]1

Participants

3

Reactant 2

HCID 1118Sulfuric AcidHCID 156611204-Bromo-2-(1,1,3-trimethyl-3-hydroxybutyl) thiophenol2×

Product 1

HCID 156611232,2,4,4-Tetramethyl-6-bromothiochroman

Procedure

A mixture of 500 mg (1.49 mmol) of 4-bromo-2-(1,1,3-trimethyl-3-hydroxybutyl) thiophenol (Compound 32) and 8 ml of 20 percent aqueous H2SO4 was heated at reflux for 24 h. The mixture was extracted with hexanes, the organic extracts were combined and washed successively with water, saturated NaHCO3, water again, saturated NaCl and then dried (MgSO4). The solvent was removed in vacuo and the residue purified by flash chromatography (silica; hexanes) to give the title compound as a colorless oil. PMR (CDCl3): & 1.35 (6H, s), 1.40 (6H, s), 1.93 (2H, s), 7.17 (1H, dd, J-8.4 Hz, 2.1 Hz), 7.23 (1H, d, J-8.4 Hz), 7.26 (1H, d, J-2.1 Hz). MS exact mass, m/e 16 284.0221 (calcd. for C13H17S Br, 284.0234).

Workup

  1. temperaturewas heated
  2. temperatureat reflux for 24 h
  3. extractionThe mixture was extracted with hexanes
  4. washwashed successively with water, saturated NaHCO3, water again
  5. dry with materialsaturated NaCl and then dried (MgSO4)
  6. customThe solvent was removed in vacuo
  7. customthe residue purified by flash chromatography (silica; hexanes)

Sources & evidence

ORD record
ord-8fdd181152aa46cabb863b3fa755a65e
Source dataset
uspto-grants-1997_04
Patent number
US05616597

Reaction notes

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