Acetic Anhydride → 2,3-Dihydro-4H-thiopyrano[2,3-b]pyridin-4-one

HRID 638876Notes

Reaction equation

HRID 638876 reaction equation
C([C:4]1[C:5]([S:10][CH2:11][CH2:12][C:13]([OH:15])=O)=[N:6][CH:7]=[CH:8][CH:9]=1)(O)=O.C([O-])(=O)C.[Na+].C(OC(=O)C)(=O)C>>[S:10]1[C:5]2=[N:6][CH:7]=[CH:8][CH:9]=[C:4]2[C:13](=[O:15])[CH2:12][CH2:11]1

Participants

4

Reactant 3

HCID 7918Acetic AnhydrideHCID 517045Sodium AcetateHCID 27640672-[(2-Carboxyethyl)sulfanyl]nicotinic acid

Product 1

HCID 120278442,3-Dihydro-4H-thiopyrano[2,3-b]pyridin-4-oneYield 27%

Procedure

A solution of 14 g. (61.6 mmol) 3-(3-Carboxy-2-pyridylthio)propionic Acid [prepared as described in lit.: J. Heterocyclic Chem., 37, 379 (2000)] and 15 g. (185 mmol, 3 eqs) of anhydrous sodium acetate, in 200 mL. of acetic anhydride was refluxed (160° C.) under stirring, N2 atm, dry conditions, for 2 hours. Cooled, diluted with 300 mL of water, basified with 30% ammonium hydroxide solution to pH 8-9, extracted with 3×200 mL chloroform. Combined organics washed with 2×60 mL Sodium bicarbonate (satn.sol), water, dried, evaporated, gave 2.8 g. (27%) of the title compound, reddish solid, m.p. 66-8° C., (M+H)+=166.2.

Workup

  1. dry with materialN2 atm, dry conditions
  2. temperatureCooled
  3. additiondiluted with 300 mL of water
  4. extractionextracted with 3×200 mL chloroform
  5. washCombined organics washed with 2×60 mL Sodium bicarbonate (satn.sol), water
  6. customdried
  7. customevaporated
  8. customgave 2.8 g

Sources & evidence

ORD record
ord-4dfe28ad1ffa4a68be8d6cb756cf782d
Source dataset
uspto-grants-2010_04
Patent number
US07691842B2

Reaction notes

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