Phosphorus oxychloride → 7-Chloro-5-(4-fluorophenyl)thieno[3,2-b]pyridine

HRID 2230080Notes

Reaction equation

HRID 2230080 reaction equation
[F:1][C:2]1[CH:7]=[CH:6][C:5]([C:8]2[N:13]=[C:12]3[CH:14]=[CH:15][S:16][C:11]3=[C:10](O)[CH:9]=2)=[CH:4][CH:3]=1.P(Cl)(Cl)([Cl:20])=O>>[Cl:20][C:10]1[CH:9]=[C:8]([C:5]2[CH:6]=[CH:7][C:2]([F:1])=[CH:3][CH:4]=2)[N:13]=[C:12]2[CH:14]=[CH:15][S:16][C:11]=12

Participants

3

Procedure

A solution of 5-(4-fluorophenyl)-thieno[3,2-b]pyridin-7-ol (1.6 g) in phosphorus oxychloride (50 mL) is refluxed for 3 hours. After the excess amount of phosphorus oxychloride is removed under vacuum, the residue is treated with ethyl acetate (20 mL) and NaOH (2N, 20 mL). The mixture is then extracted with ethyl acetate (3×20 mL). The combinded organic layers are washed with brine and dried over MgSO4. Evaporation of the solvent affords 7-chloro-5-(4-fluorophenyl)thieno[3,2-b]pyridine (1.5 g, 88% yield) as a white solid, m.p. 119-121° C.

Workup

  1. customAfter the excess amount of phosphorus oxychloride is removed under vacuum
  2. additionthe residue is treated with ethyl acetate (20 mL) and NaOH (2N, 20 mL)
  3. extractionThe mixture is then extracted with ethyl acetate (3×20 mL)
  4. washThe combinded organic layers are washed with brine
  5. dry with materialdried over MgSO4
  6. customEvaporation of the solvent

Sources & evidence

ORD record
ord-3f89f586f31645fbb7552d572f4cb297
Source dataset
uspto-grants-2002_07
Patent number
US06423711B1

Reaction notes

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