Flordipine → Diethyl 1,4-dihydro-2,6-dimethyl-1-[2-(4-morpholinyl)ethyl]-4-[2-(trifluoromethyl)phenyl]-3,5-pyridinedicarboxylate maleate

Beteiligte Stoffe

Reaktionsschritte

A solution of 1.2 g of maleic acid in 12 ml of acetone was added to a solution of 5.1 g of diethyl 1,4-dihydro-2,6-dimethyl-1-[2-(4-morpholinyl)ethyl]-4-[2-(trifluoromethyl)phenyl]-3,5-pyridinedicarboxylate in 50 ml of EtOAc. The reaction mixture was refluxed and filtered hot to yield 6.7 g of diethyl 1,4-dihydro-2,6-dimethyl-1-[2-(4-morpholinyl)ethyl]-4-[2-(trifluoromethyl)phenyl]-3,5-pyridinedicarboxylate maleate. This was partitioned between 5 parts of toluene and 10 parts of 10% NaOH, the toluene phase was dried over anhydrous Na2SO4, and dilution with 10 parts of heptane yielded 3.9 g (76%) of diethyl 1,4-dihydro-2,6-dimethyl-1-[2-(4-morpholinyl)ethyl]-4-[2-(trifluoromethyl)phenyl]-3,5-pyridinecarboxylate. Analysis by analytical HPLC indicated the presence of 0.17% of ##STR12##

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