Urea → 5-Carbethoxyuracil

HRID 1484857Notes

Reaction equation

HRID 1484857 reaction equation
[NH2:1][C:2]([NH2:4])=[O:3].CC[O-].[Na+].[Na].C([O:12][CH:13]=[C:14]([C:20](OCC)=O)[C:15]([O:17][CH2:18][CH3:19])=[O:16])C>CCO>[O:3]=[C:2]1[NH:4][C:13](=[O:12])[C:14]([C:15]([O:17][CH2:18][CH3:19])=[O:16])=[CH:20][NH:1]1

Participants

6

Reactant 4

HCID 1176UreaHCID 6871Diethyl (ethoxymethylene)malonateHCID 2723922Sodium ethoxideHCID 5360545Sodium

Product 1

HCID 1014115-CarbethoxyuracilYield 23.1%

Reagents, catalysts & solvents 1

HCID 702EthanolSolvent

Conditions

Temperature
20 °C

Procedure

Urea (12 g, 200 mmol) was added to EtOH (300 mL) containing NaOC2H5 previously prepared from sodium (5.52 g, 240 mmol, 1.2 eq). Diethyl 2-(ethoxymethylene)malonate (43.2 g, 200 mmol, 1.0 eq) was added and the solution was stirred at 20° C. for 24 h, and then stirred at 90° C. for 24 h. The alcohol was removed by reduced pressure distillation. Ice-water (100 mL) was added to dissolve the residue. The product was precipitated by adding cold dilute hydrochloric acid. The solid was filtered off to afford ethyl 2,4-dioxo-1,2,3,4-tetrahydropyrimidine-5-carboxylate (8.5 g, 23%), which was used in next step without further purification.

Workup

  1. stirringstirred at 90° C. for 24 h
  2. customThe alcohol was removed by reduced pressure distillation
  3. additionIce-water (100 mL) was added
  4. dissolutionto dissolve the residue
  5. customThe product was precipitated
  6. additionby adding cold dilute hydrochloric acid
  7. filtrationThe solid was filtered off

Sources & evidence

ORD record
ord-359067029d9d41e2a3a5f0f1d0431081
Source dataset
uspto-grants-2016_08
Patent number
US09422271B2

Reaction notes

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