Thionyl Chloride → 5-(1-Methyl-1-phenyl-ethylcarbamoyl)-3-(2-nitro-benzoylamino)-thieno[2,3-c]pyrazole-1-carboxylic Acid ethyl Ester

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

To a solution of 1.995 g (4.93 mmol) of 3-(2-Nitro-benzoylamino)-thieno[2,3-c]pyrazole-1,5-dicarboxylic acid 1-ethyl ester in toluene (35 mL) a total volume of 7.5 ml of SOCl2 was added in a step-wise manner. The suspension so obtained was heated at 80° C. for 7 hours and then evaporated to dryness. The solid was taken up with toluene and dried up twice. Next the solid was dissolved in dichloromethane (30 mL) and added drop-wise to a solution of 1.334 g (9.86 mmol) of cumylamine and DIEA (3.37 mL, 19.73 mmol) in dichloromethane (50 mL) at 0° C. The mixture was stirred and allowed to reach room temperature overnight, washed with 1 N HCl, brine, water, dried up with Na2SO4 and evaporated to dryness. The crude was then purified by silica gel chromatography (flash chromatography column) eluting with dichloromethane-methanol 99:1. The titled compound was so isolated as a colourless solid (1.80 g 70%).

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