Bromine → HCID 58526162, compound

HRID 1922318Notes

Reaction equation

HRID 1922318 reaction equation
[Al+3].[Cl-].[Cl-].[Cl-].[CH3:5][C:6]1[S:10][C:9]2[C:11](=[O:15])[CH:12]([CH3:14])[CH2:13][C:8]=2[CH:7]=1.[Br:16]Br>C(Cl)(Cl)Cl>[Br:16][C:7]1[C:8]2[CH2:13][CH:12]([CH3:14])[C:11](=[O:15])[C:9]=2[S:10][C:6]=1[CH3:5]

Participants

5

Reactant 3

HCID 24408BromineHCID 6451240Aluminum(III) ChlorideHCID 118589614,5-Dihydro-2,5-dimethyl-6H-cyclopenta[b]thiophen-6-one

Product 1

HCID 58526162HCID 58526162, compoundYield 92%

Reagents, catalysts & solvents 1

HCID 6212ChloroformSolvent3×

Procedure

To a suspension of 92.4 g (693 mmol) of AlCl3 (anhydrous powder) in 120 ml of CHCl3, 51.2 g (308 mmol) of 2,5-dimethyl-4,5-dihydro-cyclopenta[b]thiophen-6-one in 50 ml of CHCl3 was added at 0° C. over 0.5 hour. The reaction mixture was stirred for 10 minutes at this temperature; then a solution of 16.6 ml of Br2 (323 mmol) in 30 ml of CHCl3 was added dropwise over 1 hour. The resulting mixture was stirred for 1 hour at room temperature, and then poured over 1000 cm3 of ice. The organic layer was separated. The aqueous layer was extracted with 4×200 ml of CH2Cl2. The combined organic fractions were washed with 1000 ml of saturated aqueous Na2CO3, dried over K2CO3, passed through a short Silica Gel 60 column (40-63 um, d 40 mm, l 50 mm), and evaporated to dryness. Fractional distillation gave white crystalline product, b.p. 130° C./0.4 mm Hg. Yield 69.2 g (92%) of the title product contaminated with ca. 12% of 3-bromo-2,5-dimethyl-5,6-dihydro-cyclopenta[b]thiophen-4-one.

Workup

  1. additionwas added at 0° C. over 0.5 hour
  2. stirringThe resulting mixture was stirred for 1 hour at room temperature
  3. customThe organic layer was separated
  4. extractionThe aqueous layer was extracted with 4×200 ml of CH2Cl2
  5. washThe combined organic fractions were washed with 1000 ml of saturated aqueous Na2CO3
  6. dry with materialdried over K2CO3
  7. customevaporated to dryness
  8. distillationFractional distillation
  9. customgave white crystalline product, b.p. 130° C./0.4 mm Hg

Sources & evidence

ORD record
ord-adf1c23c008143ca864467a7a0aa8e1b
Source dataset
uspto-grants-2012_05
Patent number
US08173828B2

Reaction notes

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