2-Hydrazinopyridine → 4,5-Dihydro-5-methyl-1-(2-pyridinyl)-1H-pyrazol-3-amine

HRID 1731656Notes

Reaction equation

HRID 1731656 reaction equation
[Na].[NH:2]([C:4]1[CH:9]=[CH:8][CH:7]=[CH:6][N:5]=1)[NH2:3].[C:10](#[N:14])/[CH:11]=[CH:12]/[CH3:13]>C(O)C>[NH2:14][C:10]1[CH2:11][CH:12]([CH3:13])[N:2]([C:4]2[CH:9]=[CH:8][CH:7]=[CH:6][N:5]=2)[N:3]=1

Participants

5

Reactant 3

HCID 786452-HydrazinopyridineHCID 637921CrotononitrileHCID 5360545Sodium

Product 1

HCID 202281894,5-Dihydro-5-methyl-1-(2-pyridinyl)-1H-pyrazol-3-amine

Reagents, catalysts & solvents 1

HCID 702EthanolSolvent

Procedure

A 0.3 g. amount of sodium metal is dissolved in 100 ml. of absolute ethanol, then 5.45 g. of 2-hydrazinopyridine is added, followed by 3.35 g. of crotononitrile (mixture of cis or trans isomers). The reaction mixture is refluxed for 3 hours, then the solvent is removed in vacuo. Water is added and the solid is collected by filtration. The solid is recrystallized from dichloromethane-hexane, then acetone-hexane to give 3.1 g. of the product of the Example as yellow crystals, m.p. 154°-157° C.

Workup

  1. temperatureThe reaction mixture is refluxed for 3 hours
  2. customthe solvent is removed in vacuo
  3. additionWater is added
  4. filtrationthe solid is collected by filtration
  5. customThe solid is recrystallized from dichloromethane-hexane
  6. customacetone-hexane to give 3.1 g

Sources & evidence

ORD record
ord-efc2fb6eaffa4c1ca9b12fdd0242ca15
Source dataset
uspto-grants-1986_11
Patent number
US04622401

Reaction notes

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