Réaction #75503

Équation de réaction

water

bromomaleic anhydride

sodium acetate

hydrazine monohydrate

→

title compound

Rendement 37.0%

4-Bromo-1,2-dihydropyridazine-3,6-dione

Rendement 37.0%

Solvants

acetic acid water

Conditions de réaction

Traitement

1. 1
   TempératureUpon cooling the mixture
2. 2
   Extractionextracted with ethyl acetate (6×500 ml)
3. 3
   SéchageThe combined extracts were dried (MgSO4)
4. 4
   Filtrationfiltered
5. 5
   Autreevaporated

Mode opératoire

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 hours. Upon cooling the mixture was poured into water (11) and extracted with ethyl acetate (6×500 ml). The combined extracts were dried (MgSO4), filtered and evaporated to afford the title compound (20 g, 37%) as an orange solid. 1H NMR (250 MHz, d6-DMSO) δ7.68 (1H, br s). MS (ES+) m/e 193 [MH]+, 191 [MH]+. This material was used without further purification.

Source