Methyl carbazate was used in the preparation of methyl 3-(4-methyl-benzyl-idene)carbazate. It was also used in the synthesis of imidazo[1,5-d][1,2,4]triazines. It is used as pharmaceutical intermediate.
General procedure for the synthesis of methyl hydrazinecarboxylate from dimethyl carbonate: Dimethyl carbonate (1, 45.0 g, 0.50 mol) and hydrazine hydrate (29.4 mL, 0.48 mol) were added to a 250 mL round-bottomed flask and the unit was equipped with a condenser. The reaction mixture was heated to 50°C with continuous stirring for 30 minutes, followed by continued stirring at room temperature for 24 hours. After completion of the reaction, water, methanol and excess dimethyl carbonate were removed by distillation under reduced pressure. The product was dried to give white crystals of methyl hydrazinecarboxylate (2, 42.3 g) in 94% yield with a melting point of 69-70°C. The 1H NMR (300 MHz, CDCl3) data were as follows: δ 3.73 (s, 3H, CH3-O), 3.77 (d, 2H, J = 1.85 Hz, -NH2), 6.09 (s, 1H, -NH).
To remove impurities, the material is melted and pumped under vacuum until the vapours are spectroscopically pure [Caminati et al. J Am Chem Soc 108 4364 1986]. Distil it in a vacuum. [Beilstein 3 I 46.]
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