Hydrazine hydrate (1:1) → HCID 178429560, compound

Participants

Reaction Steps

##STR69## 0.54 g (1.26 mmol) of 6-[2-(4-phthalimidobutyl)-1H-benzimidazol-5-yl]-4,5-dihydro-5-methyl-3(2H)-pyridazinone and 0.3 ml (6.3 mmol) of hydrazine hydrate are boiled in 20 ml of ethanol for 2 hours. After cooling to room temperature, the solution is filtered, the filtrate is concentrated by evaporation under vacuum and the residue is taken up with 10 ml of 2N hydrochloric acid. The resulting solution is again filtered and is then adjusted to pH 11 with 3N sodium hydroxide solution and concentrated by evaporation to half its original volume. On cooling in an ice bath, a colourless solid crystallizes, which is recrystallized from ethanol. 0.26 g (69%) of crystals are obtained which melt at 185° to 187° C. and resolidify but thereafter do not melt until heated to 280° C.

Provenance & Evidence