Acetic Acid → 4-oxo-5,6-dihydro-4H-thieno[2,3-b]thiopyran-5-acetic acid

HRID 1728923Notes

Reaction equation

HRID 1728923 reaction equation
[O:1]=[C:2]1[CH:7](CC#N)[CH2:6][S:5][C:4]2[S:11][CH:12]=[CH:13][C:3]1=2.Cl.[C:15]([OH:18])(=[O:17])[CH3:16]>>[O:1]=[C:2]1[CH:7]([CH2:16][C:15]([OH:18])=[O:17])[CH2:6][S:5][C:4]2[S:11][CH:12]=[CH:13][C:3]1=2

Participants

4

Reactant 3

HCID 176Acetic AcidHCID 313Hydrochloric AcidHCID 152250344-oxo-5,6-dihydro-4H-thieno[2,3-b]thiopyran-5-acetonitrile

Product 1

HCID 152250354-oxo-5,6-dihydro-4H-thieno[2,3-b]thiopyran-5-acetic acid

Procedure

To a solution of 25 g of 4-oxo-5,6-dihydro-4H-thieno[2,3-b]thiopyran-5-acetonitrile in 100 ml of acetic acid is added 50 ml of concentrated hydrochloric acid and the mixture is refluxed under heating for 2 hours. Then, the mixture is poured into 500 ml of ice-cold water. The precipitated crystals are collected by filtration, washed with water and recrystallized from a mixed solvent of toluene and isopropyl ether to give 16.5 g of 4-oxo-5,6-dihydro-4H-thieno[2,3-b]thiopyran-5-acetic acid as white crystals, melting at 124°-127° C.

Workup

  1. temperaturethe mixture is refluxed
  2. temperatureunder heating for 2 hours
  3. filtrationThe precipitated crystals are collected by filtration
  4. washwashed with water
  5. customrecrystallized from a mixed solvent of toluene and isopropyl ether

Sources & evidence

ORD record
ord-b85495ec4ab647668a099e489f17e938
Source dataset
uspto-grants-1994_07
Patent number
US05329016

Reaction notes

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