Ethylene Glycol → 2-Bromo-1-(2-trimethylsilylethoxymethyl)-1,5-dihydropyrrolo[2,3-d]pyridazin-4-one

Participants

Reaction Conditions

Reaction Steps

To 2.1 L of ethylene glycol solution containing 430 g (1.14 mol) of ethyl 5-bromo-2-formyl-1-(2-trimethylsilylethoxymethyl)-1H-pyrrol-3-carboxylate obtained in Reference example 15-(f) was added 290 ml (5.98 mol) of hydrazine monohydrate at 60° C., and the mixture was stirred at 125° C. for 2 hours. After completion of the reaction, the reaction mixture was poured into water, and precipitated solid was collected by filtration and washed with water. The obtained crude solid was recrystallized from 3 L of a mixed solvent (toluene/cyclohexane=1/1 (V/V)) to obtain 289 g of the title compound as a beige solid. (Yield: 74%)

Provenance & Evidence