Diisopropylethylamine → 2-(6-Fluoro-1-methyl-1H-indazol-3-yl)-5-(2-trimethylsilanyl-ethoxymethyl)-5H-pyrrolo[2,3-b]pyrazine-7-carboxylic acid ((R)-2-cyano-2-methyl-ethyl)-amide

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Reaction Steps

(R)-3-Amino-2-methyl-propionitrile trifluoroacetate (crude from Step 3) was dissolved in acetonitrile (2.8 ml) to which was then added 2-(6-fluoro-1-methyl-1H-indazol-3-yl)-5-(2-trimethylsilanyl-ethoxymethyl)-5H-pyrrolo[2,3-b]pyrazine-7-carboxylic acid (80 mg, 0.18 mmol), O-benzotriazol-1-yl-N,N,N′,N′-tetramethyluronium tetrafluoroborate (70 mg, 0.22 mmol) and N,N-diisopropylethylamine (0.11 ml, 0.63 mmol). The reaction was stirred at room temperature for 18 h. Additional O-benzotriazol-1-yl-N,N,N′,N′-tetramethyluronium tetrafluoroborate (50 mg, 0.16 mmol) and N,N-diisopropylethylamine (0.11 ml, 0.63 mmol) were added and stirring was continued for 24 h. Water and ethyl acetate were added. The layers were separated and the aqueous layer was extracted twice with ethyl acetate. The combined organic layers were washed with sodium chloride solution and dried over sodium sulfate. After evaporation, the residue was purified by silica gel chromatography (methanol/dichloromethane) to afford 33 mg (36%) of 2-(6-fluoro-1-methyl-1H-indazol-3-yl)-5-(2-trimethylsilanylethoxymethyl)-5H-pyrrolo[2,3-b]pyrazine-7-carboxylic acid ((R)-2-cyano-2-methyl-ethyl)-amide. (M+Na)+=530.

Provenance & Evidence