2-Ethoxy-5-[(4-ethylpiperazino)sulfonyl]nicotinic acid → N-[3-Carbamoyl-5-ethyl-1-(2-methoxyethyl)-1H-pyrazol-4-yl]-2-ethoxy-5-(4-ethylpiperazine-1-sulfonyl)pyridine-3-carboxamide

Participants

Reaction Conditions

Reaction Steps

2-ethoxy-5-(4-ethyl-1-piperazinylsulfonyl)nicotinic acid (2.31 kg, 6.73 Mol) was suspended in ethyl acetate (16.2 L) and 1,1-carbonyldimidazole (1.09 kg, 6.73 Mol) was added at room temperature. The reaction mixture was heated at 45° C. for 40 minutes and then the reaction was stirred for a further 40 minutes at reflux. After cooling to ambient temperature 4-amino-5-ethyl-1-(2-methoxyethyl)-1H-pyrazole-3-carboxamide (1.5 kg, 7.06 Mol) was added to the cooled mixture, and the reaction stirred for a further 15 hours under reflux. The mixture was cooled filtered and the filter cake was washed with 90% water/10% ethyl acetate, (2 mL /g) to afford N-[3-carbamoyl-5-ethyl-1-(2-methoxyethyl)-1H-pyrazol-4-yl}-2-ethoxy-5-(4-ethyl-1-piperazinyl sulfonyl) nicotinamide as an off white crystalline solid, 3.16 kg, 88%. m.p.=156° C. Found: C, 51.33; H, 6.56; N, 18.36. C23H35N7O6S requires C, 51.40; H, 6.53; N, 18.25%.

Provenance & Evidence