[CH2:1]([NH:5][C:6]1[C:11]([N+:12]([O-])=O)=[C:10]([SH:15])[N:9]=[C:8]([CH3:16])[C:7]=1[C:17]([O:19][CH2:20][CH3:21])=[O:18])[CH2:2][CH2:3][CH3:4]>[Zn].C(O)(=O)C>[NH2:12][C:11]1[C:6]([NH:5][CH2:1][CH2:2][CH2:3][CH3:4])=[C:7]([C:17]([O:19][CH2:20][CH3:21])=[O:18])[C:8]([CH3:16])=[N:9][C:10]=1[SH:15]6.2 g. of 4-butylamino-6-mercapto-2-methyl-5 -nitropyridine- 3-carboxylic acid, ethyl ester (0.02 mol.) are dissolved in 25 ml. of acetic acid at reflux temperature with stirring. Zinc dust is added cautiously in small portions until the solvent is colorless. The inorganic preceipitate is then filtered off, the solvent removed and the residue dissolved in 10 ml. of methanol. The product, 5-amino-4-butylamino-6-mercapto-2-methylpyridine-3-carboxylic acid, ethyl ester, precipitates after the addition of aqueous ammonia, yield 3.6 g. (64%); m.p. 103°-105° (ethyl acetate).
Loading…