Hydrazine hydrate (1:1) → 3-Amino-5-(3,4-dimethoxy-phenyl)-1,5-dihydro-pyrazolo[4,3-c]pyridazin-6-one

HRID 241810Notes

Reaction equation

HRID 241810 reaction equation
Cl[C:2]1[C:3]([C:19]#[N:20])=[N:4][N:5]([C:9]2[CH:14]=[CH:13][C:12]([O:15][CH3:16])=[C:11]([O:17][CH3:18])[CH:10]=2)[C:6](=O)[CH:7]=1.[OH2:21].[NH2:22][NH2:23]>C(O)C>[NH2:20][C:19]1[C:3]2=[N:4][N:5]([C:9]3[CH:14]=[CH:13][C:12]([O:15][CH3:16])=[C:11]([O:17][CH3:18])[CH:10]=3)[C:6](=[O:21])[CH:7]=[C:2]2[NH:23][N:22]=1

Participants

4

Reactant 2

HCID 24654Hydrazine hydrate (1:1)HCID 578861954-Chloro-1-(3,4-dimethoxy-phenyl)-6-oxo-1,6-dihydro-pyridazine-3-carbonitrile

Product 1

HCID 103792943-Amino-5-(3,4-dimethoxy-phenyl)-1,5-dihydro-pyrazolo[4,3-c]pyridazin-6-one

Reagents, catalysts & solvents 1

HCID 702EthanolSolvent

Conditions

Temperature
100 °C

Procedure

The starting chloride (31) (190 mg) was dissolved in 500 μl of ethanol. 5 equivalents of hydrazine hydrate were added and the reaction mixture heated in a sealed tube at 100° C. for 18 hours. HPLC showed the reaction to be complete. The reaction was concentrated to dryness and purified by normal phase SiO2 chromatography eluting with (1:1) ethyl acetate-hexanes going to 100% ethyl acetate to give after drying 25 mg of desired product (I-10) as a solid. MS+: m/e=288.0 (M+H)+, 1H-NMR (500 MHz, MeOH-d4): δ 7.17 (s, 1H), 7.11 (d, 1H), 7.07 (d, 1H), 6.37 (s, 1H), 3.90 (s, 3H), ppm.

Workup

  1. customthe reaction
  2. concentrationThe reaction was concentrated to dryness
  3. custompurified by normal phase SiO2 chromatography
  4. washeluting with (1:1) ethyl acetate-hexanes going to 100% ethyl acetate
  5. customto give
  6. dry with materialafter drying 25 mg of desired product (I-10) as a solid

Sources & evidence

ORD record
ord-43370f825181409686d127637bcaa346
Source dataset
uspto-grants-2014_02
Patent number
US08653088B2

Reaction notes

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