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

HRID 2420216Notes

Reaction equation

HRID 2420216 reaction equation
[NH:1]1[CH2:8][CH2:7][C:5](=[O:6])[NH:4][C:2]1=[O:3].[C:9](OC(=O)C)(=[O:11])[CH3:10].S(=O)(=O)(O)O>C(O)(=O)C>[C:9]([N:1]1[CH2:8][CH2:7][C:5](=[O:6])[NH:4][C:2]1=[O:3])(=[O:11])[CH3:10]

Participants

5

Reactant 3

HCID 649DihydrouracilHCID 1118Sulfuric AcidHCID 7918Acetic Anhydride

Product 1

HCID 539589551-Acetyldihydropyrimidine-2,4(1H,3H)-dione

Reagents, catalysts & solvents 1

HCID 176Acetic AcidSolvent

Procedure

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:

Workup

  1. waitto boiling for ten hours
  2. distillationwas continuously distilled off by means of a fractionating column
  3. customAfter the acylation reaction
  4. distillationthe surplus acetic acid anhydride was distilled off in vacuo (15 Torr)
  5. customthe residue was recrystallized from isopropanol
  6. customThe product obtained
  7. customthe elementary analysis resulted in the following values

Sources & evidence

ORD record
ord-5f4e8bd371714ec9956a1edb9af33d55
Source dataset
uspto-grants-1978_08
Patent number
US04110242

Reaction notes

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