Phosphorus oxychloride → 7-Chloro-6-iodothieno[3,2-b]pyridine

HRID 712013Notes

Reaction equation

HRID 712013 reaction equation
[I:1][C:2]1[C:3](O)=[C:4]2[S:10][CH:9]=[CH:8][C:5]2=[N:6][CH:7]=1.P(Cl)(Cl)([Cl:14])=O>>[Cl:14][C:3]1[C:2]([I:1])=[CH:7][N:6]=[C:5]2[CH:8]=[CH:9][S:10][C:4]=12

Participants

3

Reactant 2

HCID 24813Phosphorus oxychlorideHCID 178516695HCID 178516695, compound

Product 1

HCID 867174727-Chloro-6-iodothieno[3,2-b]pyridineYield 44%

Conditions

Temperature
120 °C

Procedure

A mixture of the crude 6-iodothieno[3,2-b]pyridin-7-ol (0.99 g, 3.6 mmol) in phosphoryl chloride (20 mL) was heated at 120° C. for 2 h. The reaction was cooled to room temperature, concentrated under reduced pressure. The residue was co-evaporated with toluene, then diluted with dichloromethane and neutralized carefully with sat. NaHCO3 solution. The black tar was filtered off and the filtrate was transferred to a separation funnel. The organic layer was concentrated and purified on silica gel (eluting with 0-35% EtOAc/hexanes) to give the desired product (44% in 2 steps). LCMS calculated for C7H4ClINS (M+H)+: m/z=295.9. Found: 295.8.

Workup

  1. temperatureThe reaction was cooled to room temperature
  2. concentrationconcentrated under reduced pressure
  3. additiondiluted with dichloromethane and neutralized carefully with sat. NaHCO3 solution
  4. filtrationThe black tar was filtered off
  5. customthe filtrate was transferred to a separation funnel
  6. concentrationThe organic layer was concentrated
  7. custompurified on silica gel (eluting with 0-35% EtOAc/hexanes)

Sources & evidence

ORD record
ord-23e3db47c5dc45aaab387cd855a348cb
Source dataset
uspto-grants-2015_11
Patent number
US09181271B2

Reaction notes

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