[N:1]1[CH:6]=[CH:5][CH:4]=[CH:3][C:2]=1[C:7](O)=O.C(N1C=CN=C1)(N1C=CN=C1)=O.[CH3:22][NH:23][C:24](=[S:27])[NH:25][NH2:26].O>CN(C)C=O>[CH3:22][N:23]1[C:7]([C:2]2[CH:3]=[CH:4][CH:5]=[CH:6][N:1]=2)=[N:26][N:25]=[C:24]1[SH:27]15 g of pyridine-2-carboxylic acid (121.8 mmol) were dissolved in 150 ml of dimethylformamide. At room temperature, 29.6 g (181.8 mmol) of carbonyldiimidazole were slowly added, during which gas was evolved. Reaction was allowed to take place at 100° C. for 30 min, and then 25.6 g (242.7 mmol) of 4-methyl-3-thiosemicarbazide were added, and the mixture was stirred at 100° C. for a further 2 h. The reaction mixture was mixed with 300 ml of water. After cooling in an ice bath, the precipitated crystals were filtered off with suction and washed with a little water. The crystals were taken up in 390 ml of 1M sodium bicarbonate solution and heated to reflux for 3 h.
Wird geladen…
