Hydrazine hydrate (1:1) → 4-Chloro-6-methyl-1H-pyrazolo[4,3-c]pyridine

HRID 69312Notes

Reaction equation

HRID 69312 reaction equation
[Cl:1][C:2]1[C:7]([CH:8]=O)=[C:6](Cl)[CH:5]=[C:4]([CH3:11])[N:3]=1.O.[NH2:13][NH2:14]>ClCCCl>[Cl:1][C:2]1[C:7]2[CH:8]=[N:13][NH:14][C:6]=2[CH:5]=[C:4]([CH3:11])[N:3]=1

Participants

4

Reactant 2

HCID 24654Hydrazine hydrate (1:1)HCID 112524812,4-Dichloro-6-methylnicotinaldehyde

Product 1

HCID 730127754-Chloro-6-methyl-1H-pyrazolo[4,3-c]pyridine

Reagents, catalysts & solvents 1

HCID 111,2-DichloroethaneSolvent

Conditions

Temperature
80 °C

Procedure

To a solution of 2,4-dichloro-6-methylpyridine-3-carbaldehyde (12 g, 63 mmol) in 1,2-dichloroethane (200 mL) was added hydrazine monohydrate (9.52 g, 0.190 mol), and the reaction mixture was heated at 80° C. for 18 hours. After removal of solvents in vacuo, the residue was suspended in water (150 mL) and stirred for 30 minutes. The resulting precipitate was collected by filtration and washed with petroleum ether (2×250 mL), then was suspended in chloroform (150 mL), stirred for 30 minutes and filtered. The chloroform suspension was repeated twice to afford the product as a white solid. Yield: 6.7 g, 40 mmol, 63%. LCMS m/z 168.1 [M+H+]. 1H NMR (400 MHz, DMSO-d6) δ 13.70 (br s, 1H), 8.21 (s, 1H), 7.38 (s, 1H), 2.52 (s, 3H).

Workup

  1. customAfter removal of solvents in vacuo
  2. filtrationThe resulting precipitate was collected by filtration
  3. washwashed with petroleum ether (2×250 mL)
  4. stirringstirred for 30 minutes
  5. filtrationfiltered

Sources & evidence

ORD record
ord-62936ad7cff54f01a89a414a0e641cb5
Source dataset
uspto-grants-2014_09
Patent number
US08822494B2

Reaction notes

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