Phosphorus oxychloride → 4-Chlorothieno[3,2-c]pyridine

HRID 653406

Reaction equation

HRID 653406 reaction equation
O=[C:2]1[C:7]2[CH:8]=[CH:9][S:10][C:6]=2[CH:5]=[CH:4][NH:3]1.P(Cl)(Cl)([Cl:13])=O>>[Cl:13][C:2]1[C:7]2[CH:8]=[CH:9][S:10][C:6]=2[CH:5]=[CH:4][N:3]=1

Participants

3

Reactant 2

HCID 24813Phosphorus oxychlorideHCID 2885254H,5H-thieno(3,2-c)pyridin-4-one

Product 1

HCID 128273124-Chlorothieno[3,2-c]pyridine

Procedure

Finely divided 4-oxo-4,5-dihydrothieno[3,2-c]pyridine (105.6 g, 0.69 mole) was stirred while being treated dropwise with phosphorus oxychloride (321.5 g, 2.1 mole) at 0°. The reaction mixture was then refluxed for 2.5 hours, cooled, and cautiously poured onto crushed ice (1000 mL). The resulting solution was stirred for 30 minutes and extracted with dichloromethane (3×400 mL). The organic portions were combined, dried (MgSO4), filtered, and concentrated in vacuo to a solid which was recrystallized from acetonitrile (400 mL) affording 101 g (85%) of light yellow solid, m.p. 91°.

Workup

  1. temperatureThe reaction mixture was then refluxed for 2.5 hours
  2. temperaturecooled
  3. additioncautiously poured
  4. extractionextracted with dichloromethane (3×400 mL)
  5. dry with materialdried (MgSO4)
  6. filtrationfiltered
  7. concentrationconcentrated in vacuo to a solid which
  8. customwas recrystallized from acetonitrile (400 mL)
  9. customaffording 101 g (85%) of light yellow solid, m.p. 91°

Sources & evidence

ORD record
ord-4252db5d867043e6a8fe9427f0abce93
Source dataset
uspto-grants-1987_06
Patent number
US04677104

Linked notes

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