[CH3:1][O:2][C:3]([C:5]1[C:9]([C:10](Cl)=[O:11])=[N:8][N:7]([CH3:13])[N:6]=1)=[O:4].C(N(C(C)C)C(C)C)C>C1COCC1.C(OCC)(=O)C.[Pd]>[CH3:1][O:2][C:3]([C:5]1[C:9]([CH:10]=[O:11])=[N:8][N:7]([CH3:13])[N:6]=1)=[O:4]To a solution of freshly prepared 5-Chlorocarbonyl-2-methyl-2H-1,2,3-triazole-4-carboxylic acid methyl ester (2.7 g; ca. 13 mmol) in THF (270 ml) was added ethyl-diisopropyl-amine (1.88 g; 1.1 eq.). The mixture was hydrogenated in the presence of 2.7 g 10% Pd/C at 0-5° C. at normal pressure for 2½ hours and subsequently filtered from the catalyst. The clear solution was evaporated to give the crude as a solid which was dissolved again in ethyl acetate and stirred for a couple of minutes with silica gel. After filtration and evaporation 1.77 g (84%) of pure product as off-white crystals were obtained [m.p. 107-108° C.; 1H-NMR (300 MHz, CDCl3), δ (ppm): 10.43 (s, 1H), 4.33 (s, 3H), 4.01 (s, 3H)].
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