Dihydrouracil → 1-Acetyldihydropyrimidine-2,4(1H,3H)-dione

Participants

Reaction Steps

57 gm (0.5 mol) of 5,6-dihydrouracil and 817 gm (8 mols) of acetic acid anhydride were heated to boiling for ten hours after adding 2 ml of concentrated sulfuric acid thereto. The acetic acid produced was continuously distilled off by means of a fractionating column. After the acylation reaction had been completed, the surplus acetic acid anhydride was distilled off in vacuo (15 Torr) and the residue was recrystallized from isopropanol. The product obtained had a melting point of 191° to 193° C, and the elementary analysis resulted in the following values:

Provenance & Evidence