Iodine → 4-Chloro-2-iodothieno[2,3-B]pyridine-5-carbonitrile

HRID 1178611

Reaction equation

HRID 1178611 reaction equation
[Cl:1][C:2]1[C:7]([C:8]#[N:9])=[CH:6][N:5]=[C:4]2[S:10][CH:11]=[CH:12][C:3]=12.C([N-]C(C)C)(C)C.[Li+].CCCCCCC.O1CCCC1.C(C1C=CC=CC=1)C.[I:41]I>O1CCCC1.O.ClCCl>[Cl:1][C:2]1[C:7]([C:8]#[N:9])=[CH:6][N:5]=[C:4]2[S:10][C:11]([I:41])=[CH:12][C:3]=12

Participants

8

Reactant 4

HCID 807IodineHCID 2724682Lithium diisopropylamideHCID 114129074-Chlorothieno[2,3-b]pyridine-5-carbonitrileHCID 22742125Tetrahydrofuran heptane ethylbenzol

Product 1

HCID 100417134-Chloro-2-iodothieno[2,3-B]pyridine-5-carbonitrileYield 50.6%

Reagents, catalysts & solvents 3

HCID 962WaterSolventHCID 6344DichloromethaneSolventHCID 8028TetrahydrofuranSolvent2×

Procedure

To a solution of 4-chlorothieno[2,3-b]pyridine-5-carbonitrile (1.2 g, 6.16 mmol) [Khan, M. A.; Guarconi, A. E., J. Heterocyclic Chem., 14, 807 (1977)] in 72 mL of tetrahydrofuran at −78° C. is added dropwise 2.0 M lithium diisopropylamide in heptane/tetrahydrofuran/ethylbenzene (3.7 mL, 7.40 mmol). After stirring for 35 minutes, a solution of iodine (1.9 g, 7.40 mmol) in 8 mL of tetrahydrofuran is added dropwise over 20 minutes. The reaction mixture is stirred at −78° C. for 4 hours, then 85 mL of dichloromethane and 20 mL of water are added. The mixture is allowed to warm to room temperature. The reaction mixture is partitioned between water and dichloromethane. The organic layer is washed with a solution of sodium thiosulfate, dried over magnesium sulfate, filtered and concentrated in vacuo. The residue is purified by flash column chromatography eluting with dichloromethane to provide 1.0 g of 4-chloro-2-iodothieno[2,3-b]pyridine-5-carbonitrile as colorless crystals, mp 181–182° C.; 1H NMR (DMSO-d6) δ 8.00 (s, 1H), 8.88 (s, 1H); MS 320.8 (M+H)+.

Workup

  1. stirringThe reaction mixture is stirred at −78° C. for 4 hours
  2. customThe reaction mixture is partitioned between water and dichloromethane
  3. washThe organic layer is washed with a solution of sodium thiosulfate
  4. dry with materialdried over magnesium sulfate
  5. filtrationfiltered
  6. concentrationconcentrated in vacuo
  7. customThe residue is purified by flash column chromatography
  8. washeluting with dichloromethane

Sources & evidence

ORD record
ord-d601d2acd7984d228fa876d923b493a0
Source dataset
uspto-grants-2007_10
Patent number
US07276519B2

Linked notes

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