1-Hydroxybenzotriazole → Ethyl 3-[(3-oxo-6-pyridin-4-yl-2,3-dihydropyridazine-4-carbonyl)amino]propionate

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

0.733 g of 1-hydroxybenzotriazole, 0.833 g of β-alanine ethyl ester hydrochloride, 0.96 cm3 of N,N-diisopropylethylamine and 2.06 g of O-(7-azabenzotriazol-1-yl)-N,N,N′,N′-tetramethyluronium hexafluorophosphate were successively added to 0.94 g of 3-oxo-6-pyridin-4-yl-2,3-dihydropyridazine-4-carboxylic acid dissolved in 100 cm3 of N,N-dimethylformamide. The reaction medium was stirred for 12 hours at 19° C. The solvent was evaporated off under reduced pressure (2 kPa; 55° C.). The solid residue was triturated in 20 cm3 of dichloromethane, suction-filtered and oven-dried under reduced pressure (10 kPa; 20° C.). After purification by chromatography on silica gel (particle size 40-63 μm, under an argon pressure of 150 kPa) eluting with dichloromethane, 0.45 g of ethyl 3-[(3-oxo-6-pyridin-4-yl-2,3-dihydropyridazine-4-carbonyl)amino]propionate was obtained in the form of a white solid melting at 180° C.

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