Hydrazine → 4-Iodo-1H-pyrazolo[3,4-b]pyridine

HRID 1920839Notes

Reaction equation

HRID 1920839 reaction equation
F[C:2]1[N:9]=[CH:8][CH:7]=[C:6]([I:10])[C:3]=1[CH:4]=O.[NH2:11][NH2:12]>O1CCCC1>[I:10][C:6]1[CH:7]=[CH:8][N:9]=[C:2]2[NH:11][N:12]=[CH:4][C:3]=12

Participants

4

Reactant 2

HCID 9321HydrazineHCID 99923282-Fluoro-4-iodopyridine-3-carbaldehyde

Product 1

HCID 576428014-Iodo-1H-pyrazolo[3,4-b]pyridineYield 92%

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent2×

Conditions

Temperature
90 °C

Procedure

To a cooled solution of 2-fluoro-4-iodonicotinaldehyde (19.75 g, 78.7 mmol) in anhydrous tetrahydrofuran (100 ml) at 10° C. was carefully added 1M hydrazine in tetrahydrofuran (100 ml, 100 mmol) at such a rate that the temperature of the reaction mixture remained below 30° C. After complete addition a precipitate started to form and this was allowed to stir for a few minutes and then the vessel was sealed and heated to 90° C. for 2 hours behind a blast shield. After this time, the reaction mixture was allowed to cool down to room temperature and concentrated to dryness. The resulting yellow solid was triturated with a small amount of ethyl acetate to give the product as a pale yellow powder (17.68 g, 92% yield).

Workup

  1. customat 10° C.
  2. customremained below 30° C
  3. additionAfter complete addition a precipitate
  4. customto form
  5. customthe vessel was sealed
  6. temperatureto cool down to room temperature
  7. concentrationconcentrated to dryness
  8. customThe resulting yellow solid was triturated with a small amount of ethyl acetate

Sources & evidence

ORD record
ord-d1df4ebe56264838b4003cd609275642
Source dataset
uspto-grants-2012_05
Patent number
US08173635B2

Reaction notes

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