Trifluoroacetic acid → (+/-) 2-((3-((3R,4R)-4-amino-3-((tert-butyldimethylsilyl)oxy)piperidin-1-yl)-2-chloro-5-cyanophenyl)amino)-4-(cyclopropylamino)imidazo[2,1-f][1,2,4]triazine-7-carbonitrile

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Reaction Steps

TFA (25% in 1,2-dichloroethane, 3 mL, 9.73 mmol) was added to a solution of (+/−)-tert-butyl ((3R,4R)-3-((tert-butyldimethylsilyl)oxy)-1-(2-chloro-5-cyano-3-((7-cyano-4-(cyclopropyl(4-methoxybenzyl)amino)imidazo[2,1-f][1,2,4]triazin-2-yl)amino)phenyl)piperidin-4-yl)carbamate (Example 20B, 180 mg, 0.225 mmol) and anisole (0.098 mL, 0.901 mmol) in dichloromethane (1 mL) and the resulting reaction mixture was stirred at room temperature for 1 h. LCMS showed consumption of starting material and formation of two product (desired product and loss of Boc and PMB by-product). The reaction mixture was diluted with dichloromethane, washed cold saturated sodium bicarbonate/1N aqueous sodium hydroxide (pH 10). The layers were separated and aqueous layer was extracted with dichloromethane two more times. The combined organic layer was dried over magnesium sulfate, filtered and concentrated in vacuo, the crude product was purified by flash chromatography on silica gel using an automated ISCO system (40 g column, eluting with 1-3% methanol/dichloromethane) to give (+/−)-2-((3-((3R,4R)-4-amino-3-((tert-butyldimethylsilyl)oxy)piperidin-1-yl)-2-chloro-5-cyanophenyl)amino)-4-(cyclopropyl(4-methoxybenzyl)amino)imidazo[2,1-f][1,2,4]triazine-7-carbonitrile (114 mg) and (+/−)-2-((3-((3R,4R)-4-amino-3-((tert-butyldimethylsilyl)oxy)piperidin-1-yl)-2-chloro-5-cyanophenyl)amino)-4-(cyclopropylamino)imidazo[2,1-f][1,2,4]triazine-7-carbonitrile (30 mg).

Provenance & Evidence