Acetic Anhydride → HCID 178474728, compound

Participants

Reaction Steps

##STR59## 050 g (1.75 mmol) of 6-[2-(3-aminopropyl)-1H-benzimidazol-5-yl]-4,5-dihydro-5-methyl-3(2H)-pyridazinone are boiled with 0.34 ml (3.50 mmol) of acetic anhydride in 20 ml of glacial acetic acid for 45 minutes. The cooled solution is extensively concentrated by evaporation under vacuum and the residue is taken up with 10 ml of water. The resulting solution is adjusted to pH 9 with 10% ammonia. After concentration of this solution by evaporation to about one-third of its volume and cooling in an ice bath, a yellowish solid crystallizes, and this solid is suction filtered and then boiled up in 30 ml of acetonitrile. The solid obtained as residue is suction filtered, washed with 10 ml of acetonitrile and dried under vacuum. 0.51 g (89%) of colourless crystals melting at 244° to 246° C. are obtained.

Provenance & Evidence