Phosphorus oxychloride → HCID 21270453, compound

HRID 1905688Notes

Reaction equation

HRID 1905688 reaction equation
O[N:2]1[CH2:7][CH2:6][CH2:5][C:4]2[S:8][CH:9]=[C:10]([C:11]([O:13][CH2:14][CH3:15])=[O:12])[C:3]1=2.P(Cl)(Cl)([Cl:18])=O>>[Cl:18][N:2]1[CH2:7][CH2:6][CH2:5][C:4]2[S:8][CH:9]=[C:10]([C:11]([O:13][CH2:14][CH3:15])=[O:12])[C:3]1=2

Participants

3

Reactant 2

HCID 24813Phosphorus oxychlorideHCID 21270445HCID 21270445, compound

Product 1

HCID 21270453HCID 21270453, compound

Procedure

A solution of 2.25 g of ethyl 4-hydroxy-6,7-dihydrothieno[3,2-b]pyridine-3-carboxylate (see example 20) in 10 ml of phosphorous oxychloride is refluxed for 1 hour. After cooling excess reagent is distilled off under reduced pressure, the residue dissolved in 40 ml of dichloromethane and washed with 20 ml of 2N NaOH solution and 20 ml of water. After drying over magnesium sulfate, the filtrate is slurried with 500 mg of charcoal, filtered and evaporated to dryness. The residue is recrystallized from ether/pentane to yield ethyl 4-chloro-6,7-dihydrothieno[3,2-b]pyridine-3-carboxylate, mp 68°-70°.

Workup

  1. temperatureAfter cooling excess reagent
  2. distillationis distilled off under reduced pressure
  3. dissolutionthe residue dissolved in 40 ml of dichloromethane
  4. washwashed with 20 ml of 2N NaOH solution and 20 ml of water
  5. dry with materialAfter drying over magnesium sulfate
  6. filtrationfiltered
  7. customevaporated to dryness
  8. customThe residue is recrystallized from ether/pentane

Sources & evidence

ORD record
ord-5cf3ee2c2094473f90675297e1aeb8a9
Source dataset
uspto-grants-1987_03
Patent number
US04647566

Reaction notes

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