Potassium Carbonate → Ethyl 4-ethoxy-1-pent-3-ynyl-1H-pyrazolo[3,4-b]pyridine-5-carboxylate

HRID 1252699Notes

Reaction equation

HRID 1252699 reaction equation
[CH2:1]([O:3][C:4]([C:6]1[C:7]([O:15][CH2:16][CH3:17])=[C:8]2[CH:14]=[N:13][NH:12][C:9]2=[N:10][CH:11]=1)=[O:5])[CH3:2].C(=O)([O-])[O-].[K+].[K+].Br[CH2:25][CH2:26][C:27]#[C:28][CH3:29]>CN(C=O)C>[CH2:16]([O:15][C:7]1[C:6]([C:4]([O:3][CH2:1][CH3:2])=[O:5])=[CH:11][N:10]=[C:9]2[N:12]([CH2:29][CH2:28][C:27]#[C:26][CH3:25])[N:13]=[CH:14][C:8]=12)[CH3:17]

Participants

5

Reactant 3

HCID 11430Potassium Carbonate2×HCID 124762055-Bromopent-2-yne2×HCID 14590535CID 14590535

Product 1

HCID 14590534Ethyl 4-ethoxy-1-pent-3-ynyl-1H-pyrazolo[3,4-b]pyridine-5-carboxylate

Reagents, catalysts & solvents 1

HCID 6228DimethylformamideSolvent

Procedure

A mixture of the ethyl-4-ethoxy-1H-pyrazolo[3,4-b]pyridine-5-carboxylate of Example 19c (8.13 g.), pulverized anhydrous potassium carbonate (14.3 g.) and 1-bromo-3-pentyne (10.7 g.) in dry DMF (58 ml.) was stirred at 55°-60° for 4.5 hours. Additional quantities of 1-bromo-3-pentyne (5.3 g.) and potassium carbonate (14.3 g.) were added after 1 hour. The mixture was cooled and filtered and the filtrate evaporated at 45°-50°. The residue was diluted with water and extracted with ether and EtOAc. The combined extracts were washed with water, dried (MgSO4) and evaporated. The residue was purified by chromatography on silica gel using EtOAc/hexane 1:1 v/v as eluant to give the title compound, m.p. 93°-95°, after recrystallization from toluene.

Workup

  1. temperatureThe mixture was cooled
  2. filtrationfiltered
  3. customthe filtrate evaporated at 45°-50°
  4. additionThe residue was diluted with water
  5. extractionextracted with ether and EtOAc
  6. washThe combined extracts were washed with water
  7. dry with materialdried (MgSO4)
  8. customevaporated
  9. customThe residue was purified by chromatography on silica gel

Sources & evidence

ORD record
ord-1f7c08d7c64d4cbfa576e85975811ba1
Source dataset
uspto-grants-1988_05
Patent number
US04745121

Reaction notes

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