Urea → 5,6,7,8-Tetrahydroquinazoline-2,4(1H,3H)-dione

HRID 512121Notes

Reaction equation

HRID 512121 reaction equation
O=[C:2]1[CH2:7][CH2:6][CH2:5][CH2:4][CH:3]1[C:8]([O:10]CC)=O.[NH2:13][C:14]([NH2:16])=[O:15].[OH-].[Na+]>CC(O)=O>[NH:13]1[C:2]2[CH2:7][CH2:6][CH2:5][CH2:4][C:3]=2[C:8](=[O:10])[NH:16][C:14]1=[O:15]

Participants

5

Reactant 3

HCID 1176UreaHCID 14798Sodium HydroxideHCID 95543Ethyl 2-oxocyclohexanecarboxylate

Product 1

HCID 4718725,6,7,8-Tetrahydroquinazoline-2,4(1H,3H)-dioneYield 39%

Reagents, catalysts & solvents 1

HCID 176Acetic AcidSolvent

Conditions

Temperature
180 °C

Procedure

A mixture of ethyl 2-oxocyclohexanecarboxylate (66 g, 0.39 mol) and urea (68 g, 1.1 mol) was heated at 175-185° C. and stirred for 4-5 h. After cooled to 70° C., adjusted pH=13-14 by NaOH (a.q.), and then the mixture was stirred at 70° C. for 2 h. After cooled to r.t, the mixture was adjusted pH=6-7 by AcOH, and then extracted with DCM for several times. The combined organic layer was dried and evaporated to give the title compound (25 g, 39% yield) as brown solid which was set to do next step without any purification. MS: m/z 167.3 [M+H]+.

Workup

  1. temperatureAfter cooled to 70° C.
  2. stirringthe mixture was stirred at 70° C. for 2 h
  3. temperatureAfter cooled
  4. extractionextracted with DCM for several times
  5. customThe combined organic layer was dried
  6. customevaporated

Sources & evidence

ORD record
ord-373dd0a4984641d7ada966109cec08df
Source dataset
uspto-grants-2015_08
Patent number
US09102631B2

Reaction notes

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