[CH2:1]([C:3]1[N:7]2[C:8]([CH2:19][CH3:20])=[N:9][C:10]([N:12]3[CH2:17][CH2:16][N:15]([CH3:18])[CH2:14][CH2:13]3)=[CH:11][C:6]2=[N:5][N:4]=1)[CH3:2].C(O)=O.C(=O)(O)[O-].[Na+]>O>[CH2:1]([C:3]1[N:7]=[C:6]2[N:5]([C:8]([CH2:19][CH3:20])=[N:9][C:10]([N:12]3[CH2:17][CH2:16][N:15]([CH3:18])[CH2:14][CH2:13]3)=[CH:11]2)[N:4]=1)[CH3:2]A mixture of 3.3 g of 3,5-diethyl-7-(4-methyl-1-piperazinyl)-1,2,4-triazolo[4,3-c]pyrimidine and 50 ml of 97% formic acid was heated at reflux for 18 hours. The mixture was cooled and evaporated in vacuo to provide a residue which was diluted with 100 ml of water and carefully neutralized with sodium bicarbonate. The solution was extracted with chloroform. The extracts were dried and then concentrated to provide an oil which solidified and was collected by filtration, washed with water and dried. Recrystallization from hexane provided off-white crystalline solid 2,5-diethyl-7-(4-methyl-1-piperazinyl)-1,2,4-triazolo[1,5-c]pyrimidine, m.p. 87°-88° C. Analysis: Calculated for C14H22N6 : %C, 61.3; %H, 8.1; %N, 30.6; Found: %C, 60.6; %H, 8.1, %N, 30.6. The structural assignment was confirmed by infrared and nuclear magnetic resonance spectral analyses.
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