Phosphorus oxychloride → 7-Chloro-3-methylthieno(3,2-b)pyridine

HRID 911924Notes

Reaction equation

HRID 911924 reaction equation
P(Cl)(Cl)([Cl:3])=O.[CH3:6][C:7]1[C:11]2=[N:12][CH:13]=[CH:14][C:15](O)=[C:10]2[S:9][CH:8]=1>ClCCCl>[Cl:3][C:15]1[CH:14]=[CH:13][N:12]=[C:11]2[C:7]([CH3:6])=[CH:8][S:9][C:10]=12

Participants

4

Reactant 2

HCID 24813Phosphorus oxychlorideHCID 178431852HCID 178431852, compound

Product 1

HCID 574158647-Chloro-3-methylthieno(3,2-b)pyridineYield 55.8%

Reagents, catalysts & solvents 1

HCID 111,2-DichloroethaneSolvent

Procedure

Phosphorous oxychloride (2.2 mL, 24 mmol) in 1,2-dichloroethane (12 mL) was charged with 3-methylthieno[3,2-b]pyridin-7-ol (2.0 g, 12 mmol). The reaction stirred overnight at reflux under nitrogen. The mixture was the cooled and concentrated. Saturated NaHCO3 solution was carefully added to neutralize the residue. The biphasic mixture was extracted with dichloromethane, dried, and concentrated. Flash chromatography (15% EtOAc/hexanes) gave the title compound (1.23 g, 55%).

Workup

  1. temperatureat reflux under nitrogen
  2. temperaturecooled
  3. concentrationconcentrated
  4. additionSaturated NaHCO3 solution was carefully added
  5. extractionThe biphasic mixture was extracted with dichloromethane
  6. customdried
  7. concentrationconcentrated

Sources & evidence

ORD record
ord-442ece535ad7424db7116af6e8149339
Source dataset
uspto-grants-2011_09
Patent number
US08022223B2

Reaction notes

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