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

HRID 378942Notes

Reaction equation

HRID 378942 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

Reactant 2

HCID 24813Phosphorus oxychlorideHCID 178515622HCID 178515622, compound

Product 1

HCID 154874327-Chloro-5-(4-fluorophenyl)thieno[3,2-b]pyridineYield 88%

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 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 combined organic layers are washed with brine, dried over MgSO4, and filtered. Evaporation of the solvent gives 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 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 combined organic layers are washed with brine
  5. dry with materialdried over MgSO4
  6. filtrationfiltered
  7. customEvaporation of the solvent

Sources & evidence

ORD record
ord-7d14d8f287934d2183daa4be8ed1f16d
Source dataset
uspto-grants-2001_10
Patent number
US06297256B1

Reaction notes

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