Tetrabutylammonium Fluoride → 2-ethyl-5-chloro-1H-pyrrolo[2,3-c]pyridine

HRID 1044010Notes

Reaction equation

HRID 1044010 reaction equation
[C:1]([C:5]1[CH:10]=[C:9]([Cl:11])[N:8]=[CH:7][C:6]=1[NH:12]C(=O)OC(C)(C)C)#[C:2][CH2:3][CH3:4].CCCC[N+](CCCC)(CCCC)CCCC.[F-]>C1COCC1>[CH2:3]([C:2]1[NH:12][C:6]2=[CH:7][N:8]=[C:9]([Cl:11])[CH:10]=[C:5]2[CH:1]=1)[CH3:4]

Participants

4

Reactant 2

HCID 2724141Tetrabutylammonium FluorideHCID 57908177Tert-butyl 4-(but-1-ynyl)-6-chloropyridin-3-ylcarbamate

Product 1

HCID 579081942-ethyl-5-chloro-1H-pyrrolo[2,3-c]pyridineYield 89%

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent

Procedure

A mixture of tert-butyl 4-(but-1-ynyl)-6-chloropyridin-3-ylcarbamate (3.5 g, 12.5 mmol) and TBAF (6.65 g, 25 mmol) in THF (60 mL) was heated at reflux for 24 hours. After cooling, the mixture was poured into ice water and extracted with CH2Cl2 (100 mL×3). The combined organic layers was dried over anhydrous Na2SO4 and evaporated under reduced pressure. The residue was purified by column chromatography on silica gel (petroleum ether/ethyl acetate, 10/1) to give 2-ethyl-5-chloro-1H-pyrrolo[2,3-c]pyridine (2.0 g, 89%). 1H-NMR (CDCl3, 300 MHz) δ 8.96 (brs, H), 8.46 (s, 1H), 7.44 (s, 1H), 6.24 (s, 1H), 2.89 (q, J=7.5 Hz, 2H), 1.37 (t, J=7.5 Hz, 3H).

Workup

  1. temperaturewas heated
  2. temperatureat reflux for 24 hours
  3. temperatureAfter cooling
  4. extractionextracted with CH2Cl2 (100 mL×3)
  5. dry with materialThe combined organic layers was dried over anhydrous Na2SO4
  6. customevaporated under reduced pressure
  7. customThe residue was purified by column chromatography on silica gel (petroleum ether/ethyl acetate, 10/1)

Sources & evidence

ORD record
ord-f3eb295dcd8f47219533789e0986d616
Source dataset
uspto-grants-2013_10
Patent number
US08563573B2

Reaction notes

Loading…