反应详情

3-Benzyloxy-4-pyrone is prepared from 3-hydroxy-4-pyrone as described by Spenser et al, Canadian Journal of Chemistry, 1962, 40, 1377 and has m.p. 82°-85° C. A mixture of this compound (1 g) and ethylenediamime (0.37 g) in water (12 ml) is heated under reflux for 1 hour. The reaction mixture is evaporated to dryness and the residue is treated with concentrated hydrochloric acid (12 ml) and the mixture is heated on a steam bath for 30 minutes. The excess acid and water are evaporated under reduced pressure to give a solid brown residue. This is slurried in acetone, then filtered off and recrystallised from ethanol containing a little concentrated hydrochloric acid to give 1-(2'-aminoethyl-3-hydroxypyrid-4-one in 34% yield as colourless needles, m.p. 264°-266° C., νmax (nujol) 1050, 1540, 1600, 1635 cm-1, δ(d6DMSO), 2.85 (t, 2H), 4.35 (t, 2H), 7.1 (d, 1H), 8.1 (m, 2H).

1. temperatureis heated
2. temperatureunder reflux for 1 hour
3. customThe reaction mixture is evaporated to dryness
4. additionthe residue is treated with concentrated hydrochloric acid (12 ml)
5. temperaturethe mixture is heated on a steam bath for 30 minutes
6. customThe excess acid and water are evaporated under reduced pressure
7. customto give a solid brown residue
8. filtrationfiltered off
9. customrecrystallised from ethanol containing a little concentrated hydrochloric acid