Acetic Acid → 11N-831

Participants

Reaction Steps

A mixture of pentane-2,4-dione (20.0 g, 200 mmol), 3,4-methylenedioxybenzaldehyde (32.2 g, 200 mmol), piperidine (1.98 mL, 20.0 mmol), and HOAc (1.20 mL, 20.0 mmol) in 200 mL of isopropanol were stirred at room temperature for 3 days (no precipitate). The solvent was remove in vacuo, and the crude product was heated to 50-70° C. under reduced pressure for 0.5 hours (no solids). The crude product was chromatographed on 900 g of silica packed with 10% EtOAc-hexane. The column was eluted with increasing amounts of EtOAc (10% to 30%, 2.5%/2 L change) to give 19.1 g (41%) of the desired product as a yellow solid: mp 79-80° C. The product was used in the next step after spectral characterization.

Provenance & Evidence