Dimethylamine → Hydrochloric Acid

Participants

Reaction Conditions

Reaction Steps

5 g. crude 3-(5-nitro-1-β-acetoxyethyl-2-imidazolyl)-6-chloro-s-triazolo[4,5-b]pyridazine were dissolved in 50 ml. of a mixture of dioxan and methanol (1:1), 5.4 ml. 40% aqueous dimethylamine were added thereto, the reaction mixture was stirred for 1 hour at 60° C., evaporated almost completely, the residue triturated with 20 ml. isopropanol, 1.6 g. of solid substance being obtained which has a melting point of 164° - 167° C. After recrystallization thereof from 55 ml. isopropanol, with the addition of charcoal, there was obtained 1 g. 3-(5-nitro-1-β-acetoxyethyl-2-imidazolyl)-6-dimethylamino-s-triazolo[4,3-b]-pyridazine in the form of green-yellow crystals with a melting point of 172° - 174° C. After hydrolysis of 0.4 g. of this substance with 8 ml. 2N hydrochloric acid (90 minutes at 50° C.), the desired compound can be obtained by evaporating the hydrochloric acid solution in a vacuum at 50° C., taking up the residue with 5 ml. water, adjusting to pH 8 - 9 with concentrated aqueous ammonia, filtering off with suction the crystals obtained, washing with water and drying for 2 hours at 120° C. There was thus obtained 0.32 g. 3-(5-nitro-1-β-hydroxyethyl-2-imidazolyl)-6-dimethylamino-s-triazolo[4,3-b]pyridazine, which has a melting point of 220° - 222° C.

Provenance & Evidence