3-(2-Indolylthio)Propionic Acid → 2,3-Dihydrothiopyrano[2,3-b]indol-4(9H)-one

HRID 1086515Notes

Reaction equation

HRID 1086515 reaction equation
[NH:1]1[C:9]2[C:4](=[CH:5][CH:6]=[CH:7][CH:8]=2)[CH:3]=[C:2]1[S:10][CH2:11][CH2:12][C:13]([OH:15])=O>C(Cl)(Cl)Cl>[O:15]=[C:13]1[C:3]2[C:4]3[C:9](=[CH:8][CH:7]=[CH:6][CH:5]=3)[NH:1][C:2]=2[S:10][CH2:11][CH2:12]1

Participants

3

Reactant 1

HCID 151627253-(2-Indolylthio)Propionic Acid

Product 1

HCID 129347822,3-Dihydrothiopyrano[2,3-b]indol-4(9H)-one

Reagents, catalysts & solvents 1

HCID 6212ChloroformSolvent

Procedure

A mixture of 88.5 g (0.4 mol) of 3-(2-indolylthio)propionic acid and 300 g of polyphosphate ester in 3.5 liters of chloroform is stirred for 16 hours at room temperature and under a nitrogen atmosphere. The mixture is diluted with 3 liters of ice-cold water, the organic phase is separated after settling has occurred and the aqueous phase is extracted with chloroform. The organic phases are combined, washed with 10% strength aqueous sodium bicarbonate solution and then with water, dried and concentrated on a water bath under vacuum. The residue is recrystallized in ethanol, the crystals obtained are removed and the filtrate is concentrated.

Workup

  1. customthe organic phase is separated after settling
  2. extractionthe aqueous phase is extracted with chloroform
  3. washwashed with 10% strength aqueous sodium bicarbonate solution
  4. dry with materialwith water, dried
  5. concentrationconcentrated on a water bath under vacuum
  6. customThe residue is recrystallized in ethanol
  7. customthe crystals obtained
  8. customare removed
  9. concentrationthe filtrate is concentrated

Sources & evidence

ORD record
ord-e902670791774156a92d10e34e2158d4
Source dataset
uspto-grants-1991_07
Patent number
US05030646

Reaction notes

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