[CH3:1][O:2][C:3]([C:5]1[C:9]([N+:10]([O-])=O)=[C:8]([CH:13]([CH3:15])[CH3:14])[NH:7][N:6]=1)=[O:4]>C(O)CC.O.Cl.O=[Pt]=O>[NH2:10][C:9]1[C:5]([C:3]([O:2][CH3:1])=[O:4])=[N:6][NH:7][C:8]=1[CH:13]([CH3:15])[CH3:14]To a solution of methyl-5-isopropyl-4-nitropyrazol-3-carboxylate (7.34 g, 34.4 mmol) in 36 mL n-propanol, 6 mL water and 5.6 mL 10 M HCl was added 0.55 g PtO2. The mixture was stirred under hydrogen atmosphere (760 torr) for 9 hours. The reaction mixture was filtered and the filtrate was concentrated t dryness in vacuo. The desired amine was liberated by treatment of aq. ammonia during extraction into chloroform. The product crystallized after evaporation; yield 95%; mp=122-123. MS (EI, 70 eV, direct inlet): 183 (88; C8H13N3O2+; −1.0), 168(59), 152(3), 136(100), 108(8), 80(16), 68(20). 1H NMR (400 MHz, CDCl3): 1.31 d (6H; J=6.9 Hz), 2.93 sept (1H), 3.9 s (3H). IR (KBr, cm−1): 3399, 3296, 1710, 1626, 1584, 1302.
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