2-Thiophenecarboxaldehyde → 3-(2-thienylacryloyl)-6-methyl-2H-pyran-2,4(3H)-dione

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

To a solution of 65.0 g (0.39 mole) of dehydroacetic acid and 47.0 g (0.42 mole) of thiophene-2-aldehyde in 370 ml of benzene was added dropwise 6.8 g of piperidine with cooling in an ice-water bath. After termination of the dropwise addition, the mixture was stirred at 50° C. for 7 hours. After the reaction, the solvent was concentrated under a reduced pressure. The precipitated crystal was collected by filtration and recrystallized from toluene to obtain 58.5 g (yield: 58%) of 3-(2-thienylacryloyl)-6-methyl-2H-pyran-2,4(3H)-dione in the form of a light crystal, m.p. 162°-164° C.

Herkunft & Nachweise