Aluminum(III) Chloride → 4,4-Dimethyl-6-bromo-2-oxo-thiochroman

HRID 327284Notes

Reaction equation

HRID 327284 reaction equation
[Cl-].[Al+3].[Cl-].[Cl-].[CH3:5][C:6]([CH3:18])=[CH:7][C:8]([S:10][C:11]1[CH:16]=[CH:15][C:14]([Br:17])=[CH:13][CH:12]=1)=[O:9]>C(Cl)Cl.[Cl-].[Na+].O>[CH3:5][C:6]1([CH3:18])[C:12]2[C:11](=[CH:16][CH:15]=[C:14]([Br:17])[CH:13]=2)[S:10][C:8](=[O:9])[CH2:7]1

Participants

5

Reactant 2

HCID 6451240Aluminum(III) ChlorideHCID 15661118S-(4-bromophenyl) 3,3-dimethylthioacrylate2×

Product 1

HCID 156611194,4-Dimethyl-6-bromo-2-oxo-thiochroman

Reagents, catalysts & solvents 2

HCID 6344DichloromethaneSolvent2×HCID 57417360Sodium chloride; waterSolvent

Procedure

To a stirred, ice-cooled suspension of 15.9 g 119 mmol) of aluminum chloride in 140 ml of methylene chloride was added under nitrogen a solution of 21.64 g (79.9 mmol) of S-(4-bromophenyl) 3,3-dimethyl-thioacrylate (Compound 30) in 100 ml of methylene chloride. The mixture was then stirred at room temperature for 72 h and then poured into 250 g of an ice and brine mixture. The mixture was extracted with methylene chloride and the combined organic extracts were washed with saturated NaCl solution and then dried (MgSO4). The solvent was removed in vacuo and the residue recrystallized from hexanes to give the title compound as white crystals. PMR (CDCl3) & 1.40 (6H, s), 2.67 (2H, s), 7.31-7.40 (3H, m). MS exact mass, m/e 269.9714 (calcd. for C11H11SOBr, 269.9714).

Workup

  1. temperatureTo a stirred, ice-cooled
  2. extractionThe mixture was extracted with methylene chloride
  3. washthe combined organic extracts were washed with saturated NaCl solution
  4. dry with materialdried (MgSO4)
  5. customThe solvent was removed in vacuo
  6. customthe residue recrystallized from hexanes

Sources & evidence

ORD record
ord-1654c7487f5a4532a5651daa388ce0d5
Source dataset
uspto-grants-1993_12
Patent number
US05272156

Reaction notes

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