反应详情

1-Isopropyl-3-hydroxy-2-methylpyrid-4-one was prepared by refluxing 3-hydroxy-2-methylpyrid-4-one (Maltol) (10.0 g) with 3 equivalents of isopropylamine (99%) in 200 ml of water for 8 hours. Decolorizing charcoal was added after refluxing and the mixture was stirred for 0.5 hours. The mixture was then filtered through a medium frit filter containing 0.5 inches of Celite. The filtered solution was then concentrated in vacuo (rotary evaporator) to remove the water and excess amine, leaving a dark thick oil. The oil was then dissolved in minimal amounts of hot acetone and filtered (repeatedly) through a medium frit filter. Brownish crystals (product) remained on the frit and these were then washed (3X) with 1 ml portions of hot acetone to obtain white crystals. m.p. 239°-242 ° C.

1. temperatureafter refluxing
2. filtrationThe mixture was then filtered through a medium frit
3. filtrationfilter
4. additioncontaining 0.5 inches of Celite
5. concentrationThe filtered solution was then concentrated in vacuo (rotary evaporator)
6. customto remove the water and excess amine
7. customleaving a dark thick oil
8. filtrationfiltered (repeatedly) through a medium frit
9. filtrationfilter
10. washthese were then washed (3X) with 1 ml portions of hot acetone
11. customto obtain white crystals