Acetic Acid → 6-Chloro-3-methyl-[1,2,4]triazolo[4,3-b]pyridazine-8-carboxylic acid

HRID 521560Notes

Reaction equation

HRID 521560 reaction equation
[Cl:1][C:2]1[N:7]=[N:6][C:5]([NH:8][NH2:9])=[C:4]([C:10]([OH:12])=[O:11])[CH:3]=1.[CH3:13][C:14](O)=O>>[Cl:1][C:2]1[CH:3]=[C:4]([C:10]([OH:12])=[O:11])[C:5]2[N:6]([C:13]([CH3:14])=[N:9][N:8]=2)[N:7]=1

Participants

3

Reactant 2

HCID 176Acetic AcidHCID 205385786-Chloro-3-hydrazinylpyridazine-4-carboxylic acid

Product 1

HCID 729431896-Chloro-3-methyl-[1,2,4]triazolo[4,3-b]pyridazine-8-carboxylic acidYield 73%

Conditions

Temperature
100 °C

Procedure

A suspension of 6-chloro-3-hydrazinylpyridazine-4-carboxylic acid (4.8 g; crude product) in AcOH (100 mL) was heated at 100° C. for 3 h. The mixture was cooled to room temperature and concentrated to remove the solvent. Then the residue was washed by petroleum ether (50 mL) and recrystallized from MeOH to give the pure 6-chloro-3-methyl-[1,2,4]triazolo[4,3-b]pyridazine-8-carboxylic acid (4.0 g, 73% yield over two steps). 1H NMR (300 MHz, DMSO-d6): δ 7.2 (s, 1H), 2.66 (s, 3H). LRMS [M+H]+: 212 m/z.

Workup

  1. temperatureThe mixture was cooled to room temperature
  2. concentrationconcentrated
  3. customto remove the solvent
  4. washThen the residue was washed by petroleum ether (50 mL)
  5. customrecrystallized from MeOH

Sources & evidence

ORD record
ord-db54539e3b984eef8d2e0984425e3ebb
Source dataset
uspto-grants-2016_05
Patent number
US09328117B2

Reaction notes

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