Methanol → HCID 178496795, Verbindung

4.77 g (25.0 mmol) of methyl N′-dimethoxymethylenehydrazinecarboxylate (85% pure) were admixed with 15.3 g of a 51% strength solution of methylamine (250 mmol) in methanol, and the mixture was stirred at room temperature for 3 days. The orange-red solution was concentrated under reduced pressure to remove excess methylamine. This gave crude methyl N′-(methoxymethylaminomethylene)hydrazinecarboxylate which was then taken up in methanol (15 ml) and, with 4.95 g (27.5 mmol) of sodium methoxide solution (30% in methanol), heated to 50° C. After 3 h 50 min, the reaction mixture was cooled to room temperature, neutralized using 2N HCl and concentrated under reduced pressure. The residue was taken up in water (6 ml) and stored overnight in a fridge. The colourless crystals were filtered off, washed with cold water and dried under reduced pressure. This gave 1.70 g (52.7%) of 5-methoxy-4-methyl-2,4-dihydro-1,2,4-triazol-3-one in the form of a colourless solid. Melting point 146-148° C.