Water → 4-Bromopyridazine-3,6-diol
Reaction equation
[Br:1][C:2]1[C:3](O[C:6](=[O:8])[CH:7]=1)=[O:4].C([O-])(=O)C.[Na+].O.[NH2:15][NH2:16].O>C(O)(=O)C.O>[Br:1][C:2]1[C:3](=[O:4])[NH:15][NH:16][C:6](=[O:8])[CH:7]=1Participants
6
Reactant 4
Product 1
Reagents, catalysts & solvents 1
Conditions
- Temperature
- 100 °C
Procedure
A mixture of bromomaleic anhydride (50 g, 283 mmol) and sodium acetate (76.5 g, 562 mmol) in 40% acetic acid/water (750 ml) was treated with hydrazine monohydrate (16.5 ml, 339 mmol) at room temperature under nitrogen. The brown solution was stirred and heated at 100° C. for 18 h. Upon cooling the mixture was poured into water (1 l) and extracted with ethyl acetate (6×500 ml). The combined extracts were dried (MgSO4), filtered and evaporated to afford the title pyridazile (20 g, 37%) as an orange solid. 1H NMR (250 MHz, d6-DMSO) 7.68 (br s). MS (ES30 ) 193 [MH]+, 191 [MH]+. This material was used without further purification.
Workup
- temperatureUpon cooling the mixture
- extractionextracted with ethyl acetate (6×500 ml)
- dry with materialThe combined extracts were dried (MgSO4)
- filtrationfiltered
- customevaporated
- customto afford the title pyridazile (20 g, 37%) as an orange solid
- customThis material was used without further purification
Sources & evidence
- ORD record
- ord-7d5cdcf9b0664077b5cf9ad5db67db6c
- Source dataset
- uspto-grants-2001_09
- Patent number
- US06291460B1
Reaction notes
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