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

HRID 453566Notes

Reaction equation

HRID 453566 reaction equation
[Br:1][C:2]1[CH:3]=[C:4]([CH:8]=[O:9])[S:5][C:6]=1[CH3:7].[CH2:10](O)[CH2:11][OH:12].C1(C)C=CC(S(O)(=O)=O)=CC=1>C1(C)C=CC=CC=1>[Br:1][C:2]1[CH:3]=[C:4]([CH:8]2[O:12][CH2:11][CH2:10][O:9]2)[S:5][C:6]=1[CH3:7]

Participants

5

Reactant 3

HCID 174Ethylene GlycolHCID 6101p-Toluenesulfonic acidHCID 155382124-Bromo-5-methylthiophene-2-carbaldehyde

Product 1

HCID 532495612-(4-Bromo-5-methylthiophen-2-YL)-1,3-dioxolaneYield 93%

Reagents, catalysts & solvents 1

HCID 1140TolueneSolvent

Procedure

A mixture of 4-bromo-5-methylthiophene-2-carbaldehyde (6.0 g), ethylene glycol (100 mL), p-toluenesulfonic acid (2 mL) and toluene (100 mL) was heated under reflux for 5 hr with a Dean-Stark trap. The reaction mixture was washed with water and saturated brine, and the obtained organic layer was dried (MgSO4) and concentrated. The residue was subjected to silica gel column chromatography to give 2-(4-bromo-5-methyl-2-thienyl)-1,3-dioxolane (6.96 g, yield 93%) as a yellow oil from a fraction eluted with ethyl acetate-hexane (1:5, volume ratio).

Workup

  1. temperaturewas heated
  2. temperatureunder reflux for 5 hr with a Dean-Stark trap
  3. washThe reaction mixture was washed with water and saturated brine
  4. dry with materialthe obtained organic layer was dried (MgSO4)
  5. concentrationconcentrated

Sources & evidence

ORD record
ord-e241330502e54d08a33123291cc4c035
Source dataset
uspto-grants-2013_07
Patent number
US08492405B2

Reaction notes

Loading…