Ethylene Glycol → 2-(5-Bromo-4-methylthiophen-2-yl)-1,3-dioxolane

HRID 390762Notes

Reaction equation

HRID 390762 reaction equation
[CH2:1]([OH:4])[CH2:2][OH:3].C1(C)C=CC(S(O)(=O)=O)=CC=1.[Br:16][C:17]1[S:18][C:19]([CH:23]=O)=[CH:20][C:21]=1[CH3:22]>C1(C)C=CC=CC=1>[Br:16][C:17]1[S:18][C:19]([CH:23]2[O:4][CH2:1][CH2:2][O:3]2)=[CH:20][C:21]=1[CH3:22]

Participants

5

Reactant 3

HCID 174Ethylene GlycolHCID 6101p-Toluenesulfonic acidHCID 164141925-Bromo-4-methylthiophene-2-carbaldehyde

Product 1

HCID 584181152-(5-Bromo-4-methylthiophen-2-yl)-1,3-dioxolane

Reagents, catalysts & solvents 1

HCID 1140TolueneSolvent

Procedure

Ethylene glycol (2.18 ml) and p-toluenesulfonic acid (0.74 g) is added to a solution of 2-brom-3-methyl-5-formylthiophene (4.0 g) in toluene (98 ml) in a Dean-Stark apparatus. After 18 hours at reflux, the reaction is quenched with water. The organic phase is separated and the aqueous phase is extracted three times with ethyl acetate. The combined organic phases are dried over Na2SO4 and concentrated in vacuo. The crude product is purified on a semi-preparative HPLC to yield 2-(5-bromo-4-methyl-thiophen-2-yl)-[1,3]dioxolane (4.04 g) as a yellow oil MS (HPLC/MS): 250 (MH+). Retention time: 4.02 min.

Workup

  1. temperatureAfter 18 hours at reflux
  2. customthe reaction is quenched with water
  3. customThe organic phase is separated
  4. extractionthe aqueous phase is extracted three times with ethyl acetate
  5. dry with materialThe combined organic phases are dried over Na2SO4
  6. concentrationconcentrated in vacuo
  7. customThe crude product is purified on a semi-preparative HPLC

Sources & evidence

ORD record
ord-818f6536b1fa44f1ac5bb4e70627f6c4
Source dataset
uspto-grants-2013_02
Patent number
US08383659B2

Reaction notes

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