Triethylamine → 1-ethyl-3-methyl-1H-pyrazolo[3,4-b]pyridine-5-carboxylic acid, ethyl ester

HRID 237115Notes

Reaction equation

HRID 237115 reaction equation
Cl[C:2]1[C:7]([C:8]([O:10][CH2:11][CH3:12])=[O:9])=[CH:6][N:5]=[C:4]2[N:13]([CH2:17][CH3:18])[N:14]=[C:15]([CH3:16])[C:3]=12.C(N(CC)CC)C>[Pd].C(O)(=O)C>[CH2:17]([N:13]1[C:4]2=[N:5][CH:6]=[C:7]([C:8]([O:10][CH2:11][CH3:12])=[O:9])[CH:2]=[C:3]2[C:15]([CH3:16])=[N:14]1)[CH3:18]

Participants

5

Reactant 2

HCID 8471TriethylamineHCID 1473447ethyl 4-chloro-1-ethyl-3-methyl-1H-pyrazolo[3,4-b]pyridine-5-carboxylate

Product 1

HCID 544745731-ethyl-3-methyl-1H-pyrazolo[3,4-b]pyridine-5-carboxylic acid, ethyl ester

Reagents, catalysts & solvents 2

HCID 23938PalladiumCatalystHCID 176Acetic AcidSolvent

Procedure

To 80.3 g. of 4-chloro-1-ethyl-3-methyl-1H-pyrazolo[3,4-b]pyridine-5-carboxylic acid, ethyl ester (0.3 mol.) [prepared according to Journal of Heterocyclic Chemistry 9, 235-253 (1972)] dissolved in 270 ml. glacial acetic acid, are added 33.4 g. of triethylamine (0.33 mol.) and 7.5 g. of palladium on charcoal (10%). The mixture is hydrogenated at room temperature and a pressure of 2.5 atm. After about 19 hours the theoretical amount of hydrogen is absorbed. Then the catalyst is filtered off and the filtrate evaporated. The residue is treated with 200 ml. of water and extracted with ether. The combined ether extracts are dried and the ether distilled off. The oily 1-ethyl-3-methyl-1H-pyrazolo[3,4-b]pyridine-5-carboxylic acid, ethyl ester is distilled in vacuo; b.p.0.3 144°-146°, which after a short time begins to crystallize, yield: 64.5 g. (92%).

Workup

  1. customis hydrogenated at room temperature
  2. customAfter about 19 hours the theoretical amount of hydrogen is absorbed
  3. filtrationThen the catalyst is filtered off
  4. customthe filtrate evaporated
  5. additionThe residue is treated with 200 ml
  6. extractionof water and extracted with ether
  7. dry with materialThe combined ether extracts are dried
  8. distillationthe ether distilled off
  9. distillationThe oily 1-ethyl-3-methyl-1H-pyrazolo[3,4-b]pyridine-5-carboxylic acid, ethyl ester is distilled in vacuo
  10. customb.p.0.3 144°-146°, which
  11. customto crystallize

Sources & evidence

ORD record
ord-f30bca0cbc4d42f6b522f33d06841b13
Source dataset
uspto-grants-1979_06
Patent number
US04159380

Reaction notes

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