2,2-Dimethyl-1,3-dioxane-4,6-dione → HCID 58197305, compound

Participants

Reaction Steps

Similar procedures to those referenced in Tett. Lett. (2006), 651, D. Ramachary; Eur. J. Org. Chem. (2008), 975, D. Ramachary were employed. To a 5 L 3-necked flask fitted with an overhead mechanical stirrer was added 4-(trifluoromethyl)benzaldehyde (43.5 g, 250 mmol) followed by the addition of anhydrous EtOH (3,000 mL), Meldrum's acid (37.5 g, 260 mmol), diethyl 2,6-dimethyl-1,4-dihydropyridine-3,5-dicarboxylate (67.5 g, 266 mmol) and L-proline (6.0 g, 51 mmol) at room temperature. The yellowish reaction mixture was stirred at room temperature under N2. An aliquot was removed after 4 hours and rinsed with EtOH and then Et2O, and air dried. The 1H NMR of this aliquot showed the reaction to be complete. The full reaction was stopped and the white precipitate from the reaction was collected by filtration and rinsed with EtOH and then Et2O and dried under vacuum to provide the title compound in the first crop as a fine white solid. The yellowish mother liquors were concentrated and allowed to crystallize overnight from EtOH and the solid material was collected as before to provide the title compound.

Provenance & Evidence