[CH3:1][NH:2][CH3:3].[CH:4]([N:7]([C:14]#[N:15])[NH:8][C:9]([O:11]CC)=O)([CH3:6])[CH3:5]>C(O)C>[CH3:1][N:2]([CH3:3])[C:14]1[N:7]([CH:4]([CH3:5])[CH3:6])[NH:8][C:9](=[O:11])[N:15]=1To a solution of 100 ml of 33 % strength dimethylamine in absolute ethanol are added dropwise 35 g (0.2 mol) of ethyl 2-isopropyl-2-cyano-hydrazinecarboxylate. The solution is first stirred for 8 hours at room temperature and then for 1.5 hours at the reflux temperature. Concentration in a rotary evaporator gives an oily residue which slowly crystallizes on standing. Recrystallization from cyclohexane/ethyl acetate (4:1 by vol.) gives 30 g (88 % of theory) of 5-dimethylamino-1-isopropyl-1,2-dihydro-3H-1,2,4-triazol -3-one having a melting point of 111° C.
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