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

HRID 6540Notes

Reaction equation

HRID 6540 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 71) 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): δ 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 284.0221 (calcd. for C13H17 S Br, 284.0234).

Workup

  1. temperaturewas heated
  2. temperatureat reflux for 24 h
  3. extractionThe mixture was extracted with hexanes the organic extracts
  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-3b023fa40f894243abce5a27de4b2fb6
Source dataset
uspto-grants-1993_09
Patent number
US05248777

Reaction notes

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