Hydrazine hydrate (1:1) → 6-Chloroimidazo[1,2-b]pyridazine-8-carboxylic acid hydrazide

HRID 1969104Notes

Reaction equation

HRID 1969104 reaction equation
C([O:3][C:4]([C:6]1[C:7]2[N:8]([CH:13]=[CH:14][N:15]=2)[N:9]=[C:10]([Cl:12])[CH:11]=1)=O)C.O.[NH2:17][NH2:18]>C(O)C>[Cl:12][C:10]1[CH:11]=[C:6]([C:4]([NH:17][NH2:18])=[O:3])[C:7]2[N:8]([CH:13]=[CH:14][N:15]=2)[N:9]=1

Participants

4

Reactant 2

HCID 24654Hydrazine hydrate (1:1)HCID 57786728Ethyl 6-chloroimidazo[1,2-b]pyridazine-8-carboxylate

Product 1

HCID 577866686-Chloroimidazo[1,2-b]pyridazine-8-carboxylic acid hydrazideYield 57%

Reagents, catalysts & solvents 1

HCID 702EthanolSolvent

Procedure

To a solution of crude 6-chloro-imidazo[1,2-b]pyridazine-8-carboxylic acid ethyl ester (5.00 g, “22 mmol”) in 40 mL of ethanol at 0-5° C. was added 10 mL of hydrazine hydrate. Yellow solid immediately precipitated. After 15 min. at 0-5° C., the solid was isolated by Buchner filtration, rinsing well with ice-cold ethanol (250 mL total) and dried by sucking air through then in vacuo. A small amount of additional solid precipated from the filtrate and was isolated and dried similarly to the first crop. A total of 2.38 g (57% over three steps) of 6-chloro-imidazo[1,2-b]pyridazine-8-carboxylic acid hydrazide was isolated as a yellow solid.

Workup

  1. customYellow solid immediately precipitated
  2. customthe solid was isolated by Buchner filtration
  3. washrinsing well with ice-cold ethanol (250 mL total)
  4. customdried
  5. customA small amount of additional solid precipated from the filtrate and was isolated
  6. customdried similarly to the first crop

Sources & evidence

ORD record
ord-7768b1badc6d42ada02d6eae700bea02
Source dataset
uspto-grants-2013_04
Patent number
US08426441B2

Reaction notes

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