Triethylamine → 2-{[(3-{[3-{[(5-Chloro-2-thienyl)sulfonyl]amino}-4-(methyloxy)-1H-indazol-1-yl]methyl}phenyl)methyl]amino}-1,1-dimethyl-2-oxoethyl acetate

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Reaction Steps

A stirring suspension of N-[1-{[3-(aminomethyl)phenyl]methyl}-4-(methyloxy)-1H-indazol-3-yl]-5-chloro-2-thiophenesulfonamide (40.5 g, 87 mmol) in dichloromethane (1000 mL) and triethylamine (36.4 mL, 262 mmol) was cooled down and then 2-chloro-1,1-dimethyl-2-oxoethyl acetate (12.52 mL, 87 mmol) was added dropwise. The reaction mixture was stirred at room temperature under nitrogen for 1 h and 20 min. It was then washed with 2M HCl (300 ml), NaHCO3 solution (300 ml), brine, dried over magnesium sulphate and filtered. The filtrate was evaporated in vacuo to give a white solid. The residue was dissolved in DCM and loaded onto a 1500 g silica column and eluted with 40-100% ethyl acetate in cyclohexane over 8 CV. The required fractions were combined and evaporated in vacuo to give the title compound in two batches (37.87 g, 73%) and (3.39 g) as white foams. HPLC showed that the latter batch was not pure, therefore it was purified again on a 120 g silica column using a gradient of 40-75% ethyl acetate in cyclohexane over 8 CV. The required fractions were combined and evaporated in vacuo to give the title compound (2.16 g, 4%) as a white foam.

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