Acetic Acid → 2-Bromo-3-(but-2-ynyl)-3,5-dihydro-imidazo[4,5-d]pyridazin-4-one

HRID 2116780Notes

Reaction equation

HRID 2116780 reaction equation
O.[NH2:2][NH2:3].[Br:4][C:5]1[N:9]([CH2:10][C:11]#[C:12][CH3:13])[C:8]([C:14]([O:16]CC)=O)=[C:7]([CH:19]=O)[N:6]=1.C(O)(=O)C>C(O)C>[Br:4][C:5]1[N:9]([CH2:10][C:11]#[C:12][CH3:13])[C:8]2[C:14](=[O:16])[NH:3][N:2]=[CH:19][C:7]=2[N:6]=1

Participants

5

Reactant 3

HCID 176Acetic AcidHCID 24654Hydrazine hydrate (1:1)HCID 11522264ethyl 2-bromo-3-(but-2-ynyl)-5-formyl-3H-imidazole-4-carboxylate

Product 1

HCID 219476582-Bromo-3-(but-2-ynyl)-3,5-dihydro-imidazo[4,5-d]pyridazin-4-one

Reagents, catalysts & solvents 1

HCID 702EthanolSolvent

Conditions

Temperature
100 °C

Procedure

6.31 ml (0.126 mol) hydrazine hydrate were added drop-wise at ambient temperature to a solution of 35.0 g (0.117 mol) ethyl 2-bromo-3-(but-2-ynyl)-5-formyl-3H-imidazole-4-carboxylate in 400 ml of ethanol. After 30 min stirring 27 ml (0.472 mol) concentrated acetic acid were added and the solution was then stirred for 1 h at 100° C. After cooling the precipitated solid was suction filtered, washed with ethanol and diethyl ether and dried. The solid was further purified by re-crystallization from EtOH.

Workup

  1. additionwere added
  2. temperatureAfter cooling the precipitated solid
  3. filtrationfiltered
  4. washwashed with ethanol and diethyl ether
  5. customdried
  6. customThe solid was further purified by re-crystallization from EtOH

Sources & evidence

ORD record
ord-bdaf642b29db445d96c4e066103cd9b6
Source dataset
uspto-grants-2008_10
Patent number
US07439370B2

Reaction notes

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