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

HRID 2166996Notes

Reaction equation

HRID 2166996 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-86f0397b59dd43bcb494eed53798f889
Source dataset
uspto-grants-2015_06
Patent number
US09044389B2

Reaction notes

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