Toluene → 2-(Benzo[b]thiophen-5-yl)-1,3-dioxolane

HRID 2232373Notes

Reaction equation

HRID 2232373 reaction equation
[CH:1]([C:3]1[CH:11]=[CH:10][C:6]2[S:7][CH:8]=[CH:9][C:5]=2[CH:4]=1)=[O:2].[C:12]1([CH3:18])C=CC=CC=1.C1(C)C=CC(S(O)(=O)=[O:26])=CC=1>C(O)CO>[O:2]1[CH2:18][CH2:12][O:26][CH:1]1[C:3]1[CH:11]=[CH:10][C:6]2[S:7][CH:8]=[CH:9][C:5]=2[CH:4]=1

Participants

5

Reactant 3

HCID 1140TolueneHCID 6101p-Toluenesulfonic acidHCID 139097Benzo(b)thiophene-5-carboxaldehyde

Product 1

HCID 139229092-(Benzo[b]thiophen-5-yl)-1,3-dioxolaneYield 79%

Reagents, catalysts & solvents 1

HCID 174Ethylene GlycolSolvent

Procedure

A solution of product from Step A (16.4 g, 0.1 mol), toluene (300 ml), p-toluenesulfonic acid (1.0 g) and ethylene glycol (20 ml) was heated at reflux with the aid of a Dean-Stark trap. After 6 hours, the organic layer was cooled, washed with saturated Na2CO3. The Na2CO3 layer was extracted with ethyl acetate (2x). The combined organic extracts were dried, filtered and concentrated to dryness. The residue was distilled at 149°-153° C. at 0.3 mm Hg to yield 16.4 g (79%) of product.

Workup

  1. temperatureat reflux with the aid of a Dean-Stark trap
  2. temperaturethe organic layer was cooled
  3. washwashed with saturated Na2CO3
  4. extractionThe Na2CO3 layer was extracted with ethyl acetate (2x)
  5. customThe combined organic extracts were dried
  6. filtrationfiltered
  7. concentrationconcentrated to dryness
  8. distillationThe residue was distilled at 149°-153° C. at 0.3 mm Hg

Sources & evidence

ORD record
ord-a7a9c28eeef240d3965b16f7ef3748c3
Source dataset
uspto-grants-1988_11
Patent number
US04788192

Reaction notes

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