[C:1]([C:4]1[CH:9]=[C:8]([NH2:10])[C:7]([CH2:11][CH2:12][CH2:13][CH3:14])=[C:6](Cl)[N:5]=1)(=[O:3])[NH2:2].C(C1C=C(Cl)C(CCCC)=C(N)N=1)(=O)N.[H][H]>CO.[Pd]>[C:1]([C:4]1[CH:9]=[C:8]([NH2:10])[C:7]([CH2:11][CH2:12][CH2:13][CH3:14])=[CH:6][N:5]=1)(=[O:3])[NH2:2]11.4 g (0.05 mol) of the isomer mixture of 2-carbamoyl-4-amino-5-n-butyl-6-chloro-pyridine and 2-carbamoyl-4-chloro-5-n-butyl-6-amino-pyridine, dissolved in 120 ml of pure methanol, are hydrogenated in the presence of 1.5 g of palladium on charcoal. After the calculated amount of hydrogen has been taken up, the catalyst is filtered off and the filtrate is evaporated to dryness. The residue is rendered alkaline with 2 N sodium carbonate solution and extracted with ether. The crystalline product which is soluble in neither sodium carbonate solution nor in ether is filtered off and rinsed with water. The white crystals are dried for 20 hours at 70° in a high vacuum. 2-Carbamoyl-4-amino-5-n-butyl-pyridine of the formula ##STR33## and of melting point 186°-190° is thus obtained.
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