Cl.NO.C([N:7](CC)C(C)C)(C)C.C(OC(=O)[NH:17][C:18](=S)[NH:19][C:20]1[C:25]([CH3:26])=[N:24][CH:23]=[C:22]([CH3:27])[N:21]=1)C>C(O)C.O>[CH3:27][C:22]1[N:21]2[N:7]=[C:18]([NH2:17])[N:19]=[C:20]2[C:25]([CH3:26])=[N:24][CH:23]=1
A mixture of hydroxylamine hydrochloride (13.68 g, 196.85 mmol) and N,N-diisopropylethylamine (20.6 ml, 118.11 mmol) in ethanol (200 ml) was stirred for 10 minutes at 25° C. To this mixture was then added ethyl-N-[(3,6-dimethylpyrazin-2-yl)carbamothioyl]carbamate (10 g, 39.37 mmol), and the resultant mixture was heated under reflux for 16 hours. The resultant mixture was diluted with water (100 ml), stirred for 10 min, and extracted twice with ethyl acetate. The combined organic layers were washed with brine, dried over anhydrous sodium sulfate, filtered and evaporated. The crude material thus obtained was triturated with hexane affording 5,8-dimethyl-[1,2,4]triazolo[1,5-a]pyrazin-2-ylamine (2.4 g, 71.87%) as a white solid. MS: m/z=164 (M+H+)
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