反应详情

In a manner analogous to that described in Example 13, from 1 g. 3-(5-nitro-1-methyl-2-imidazolyl)-6-amino-s-triazolo[ 4,3-b]pyridazine and 10 ml. ethyl orthoformate, there was prepared crude 3-(5-nitro-1-methyl-2-imidazolyl)-6-ethoxymethyleneamino-s-triazolo[4,3-b]pyridazine which, with 13 ml. of a solvent mixture of isopropanol and dioxan (7:3) and 1.1 ml. diethylamine gave, after a reaction time of 30 minutes at 20° C., subsequent evaporation of the solution in a vacuum at a bath temperature of 80° C., trituration of the residue with a little isopropanol and water and drying for 2 hours at 120° C. in a vaccum, 0.84 g. of the desired 3-(5-nitro-1-methyl-2-imidazolyl)-6-(diethylaminomethyleneamino)-s-triazolo[4,3-b]pyridazine which has a melting point of 155° - 156° C.