HCID 86619018, compound → Ethyl 7-chloro-1H-pyrrolo[2,3-c]pyridine-2-carboxylate

HRID 1821804Notes

Reaction equation

HRID 1821804 reaction equation
[Cl:1][C:2]1[C:7]([N+:8]([O-])=O)=[C:6](/[CH:11]=[C:12](\[O-])/[C:13]([O:15][CH2:16][CH3:17])=[O:14])[CH:5]=[CH:4][N:3]=1.[K+]>C(O)(=O)C.[Fe]>[Cl:1][C:2]1[N:3]=[CH:4][CH:5]=[C:6]2[CH:11]=[C:12]([C:13]([O:15][CH2:16][CH3:17])=[O:14])[NH:8][C:7]=12

Participants

4

Reactant 1

HCID 86619018HCID 86619018, compound

Product 1

HCID 46839972Ethyl 7-chloro-1H-pyrrolo[2,3-c]pyridine-2-carboxylateYield 72%

Reagents, catalysts & solvents 2

HCID 23925IronCatalystHCID 176Acetic AcidSolvent

Conditions

Temperature
60 °C

Procedure

Potassium (1Z)-1-(2-chloro-3-nitropyridin-4-yl)-3-ethoxy-3-oxoprop-1-en-2-olate (19.8 g, 63.6 mmol) was dissolved in acetic acid (908 mL) and the solution was treated with iron powder (14.6 g, 280.9 mmol). The reaction mixture was warmed to 60° C. and stirred overnight (18.5 h). TLC analysis indicated consumption of the starting material, therefore the reaction mixture was filtered through diatomaceous earth to remove the catalyst. The filtrate was concentrated to dryness. The residue was treated with methylene chloride (ca. 400 mL) and filtered through a plug of silica. Eluting with methylene chloride removed insolubles, and further elution with methylene chloride/ethyl acetate (50:50) provided ethyl 7-chloro-1H-pyrrolo[2,3-c]pyridine-2-carboxylate (10.3 g, 45.8 mmol, yield 72%) as a yellow solid after concentration: Rf 0.80 (silica gel, 50:50 hexanes/ethyl acetate); mp 152-157° C.; 1H NMR (300 MHz, CD3OD) δ1.43 (3H, t, J=7.0 Hz), 4.44 (2H, q, J=7.1 Hz), 7.27 (1H, s), 7.65 (1H, d, J=5.7 Hz), 7.95 (1H, d, J=5.4 Hz); ESI MS m/z 224 [C10H9ClN2O2+H]+; HPLC (Method A) >99% (AUC), tR=16.6 min.

Workup

  1. customconsumption of the starting material
  2. filtrationthe reaction mixture was filtered through diatomaceous earth
  3. customto remove the catalyst
  4. concentrationThe filtrate was concentrated to dryness
  5. additionThe residue was treated with methylene chloride (ca. 400 mL)
  6. filtrationfiltered through a plug of silica
  7. washEluting with methylene chloride removed insolubles, and further elution with methylene chloride/ethyl acetate (50:50)

Sources & evidence

ORD record
ord-5f64137f5dc3426f8b456c6cfa5883c3
Source dataset
uspto-grants-2009_10
Patent number
US07608627B2

Reaction notes

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