Trifluoroacetic acid → HCID 23369751, compound

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Reaction Steps

The compound obtained in Example 232 (2.75 g, 6.9 mmol) was added to trifluoroacetic acid (15 ml) under cooling conditions, and the mixture was stirred for 30 minutes. The reaction mixture was subjected to distillation under reduced pressure, and the residue was purified by silica gel column chromatography (chloroform: methanol =3:1). The obtained crystals were dissolved in chloroform-methanol (3:1, 20 ml), and 5% HCl-methanol (10 ml) was added thereto while cooling on ice. The mixture was condensed under reduced pressure. The resultant residue was recrystallized from methanol--ether. 2.0 g of the title compound was obtained as pale yellow crystals (86.0%).

Provenance & Evidence