Dichloromethane → 2-(Trimethylsilyl)ethyl 4-[4-(4-acetylpiperazin-1-yl)phenyl]isoquinoline-6-carboxylate

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Reaction Steps

Into dichloromethane (5 mL), 2-(trimethylsilyl)ethyl 4-{4-[4-(tert-butoxycarbonyl)piperazin-1-yl]phenyl}isoquinoline-6-carboxylate (103 mg, 0.193 mmol) synthesized in Example 16 (16a) was dissolved, to which trifluoroacetic acid (0.5 mL) was added, followed by stirring at room temperature for three hours. After concentration, the resulting mixture was diluted with dichloromethane (20 mL) and neutralized with a saturated aqueous solution of sodium bicarbonate (15 mL). The resulting organic layer was dried over sodium sulfate and filtered. The solvent was distilled off under reduced pressure. The residue thus obtained was dissolved in pyridine (5 mL), to which anhydrous acetic acid (0.5 mL) was added, followed by stirring at room temperature overnight. After concentration, the resulting mixture was diluted with dichloromethane (20 mL) and neutralized with a saturated aqueous solution of sodium bicarbonate (15 mL). The solution thus obtained was extracted with dichloromethane (20 mL), and the resulting organic layer was dried over sodium sulfate and filtered. The solvent was distilled off under reduced pressure and the resulting product was purified by thin layer chromatography (dichloromethane:methanol=97:3) to give the desired title compound (54 mg, yield 58%).

Provenance & Evidence