[NH2:1][C:2]1[NH:6][N:5]=[C:4]([N:7]2[CH2:12][CH2:11][CH2:10][CH2:9][CH2:8]2)[N:3]=1.O=[C:14]1[CH2:19][CH2:18][CH2:17][S:16][CH:15]1[C:20](OCC)=[O:21]>C(O)(=O)C.O>[N:7]1([C:4]2[N:3]=[C:2]3[NH:1][C:14]4[CH2:19][CH2:18][CH2:17][S:16][C:15]=4[C:20](=[O:21])[N:6]3[N:5]=2)[CH2:12][CH2:11][CH2:10][CH2:9][CH2:8]116.7 g (0.1 mole) of 5-amino-3-piperidino-1H-1,2,4-triazole are dissolved in 10 ml of acetic acid and 18.8 g (0.1 mole) of ethyl 3-oxo-3,4,5,6-tetrahydro-2H-thiopyrane-2-carboxylate are added, then the reaction mixture is boiled for 10 minutes. The thick crystal mass thus obtained is diluted with 100 ml of water, the precipitated product is filtered off, washed with i-propanol and recrystallized from dimethylformamide. Thus 23.3 g (82.2%) of 2-piperidino-5,7,8,9-tetrahydrothiopyrano[3,2-d]-1,2,4-triazolo[1,5-a]pyrimidine-5(10H)-one are obtained with a melting point above 350° C.
Loading…
