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

HRID 1198017Notes

Reaction equation

HRID 1198017 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 (6 H, s), 1.40 (6 H, s), 1.93 (2 H, s), 7.17 (1 H, dd, J~8.4 Hz, 2.1 Hz), 7.23 (1 H, d, J~8.4 Hz), 7.26 (1 H, d, J~2.1 Hz). MS exact mass, m/e 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-f69dbffc244146ccad3c49c28fdb2ded
Source dataset
uspto-grants-1994_01
Patent number
US05278318

Reaction notes

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