50 g 4-pyridone was dissolved in 300 ml 20% hydrochloric acid and slowly
mixed with 180 g of chloroiodide in 200 ml 20% hydrochloric acid. Then the
obtained dark solution was strong alkalized with sodium hydroxide. The
solvent was removed to dryness and sodium salt diiod-4-pyridone was
obtained. It was dissolved in water, filtered and equivalent quantity of glacial
acetic acid or hydrochloric acid was added to give 3,5-diiod-4-pyridone as a
powder. 34.5 g 3,5-diiod-pyridone was dissolved in 100 ml 1 N NaOH by
heating on a water bath and added to a 15 g of monochlorohydrine added.
The mixture was heated on water bath before a dense pasty mass obtained. It
was filtered off and treated with 1 N NaOH. The obtained 1-(2,3-
dihydroxypropyl)-3,5-diiodo-4(1H)-pyridinone was recrystallized from diluted
hydrochloric acid. MP: 161°C.
