Guanidine Hydrochloride → 2-Amino-3H-quinazolin-4-one

HRID 973562Notes

Reaction equation

HRID 973562 reaction equation
Cl.[NH2:2][C:3]([NH2:5])=[NH:4].C[O-].[Na+].[C:9](OC)(=[O:17])[C:10]1[C:11](=[CH:13][CH:14]=[CH:15][CH:16]=1)N>C(O)CCC>[NH2:4][C:3]1[NH:5][C:9](=[O:17])[C:10]2[C:16](=[CH:15][CH:14]=[CH:13][CH:11]=2)[N:2]=1

Participants

5

Reactant 3

HCID 5742Guanidine HydrochlorideHCID 8635Methyl AnthranilateHCID 10942334Sodium Methoxide

Product 1

HCID 1354038142-Amino-3H-quinazolin-4-oneYield 19%

Reagents, catalysts & solvents 1

HCID 2631-ButanolSolvent2×

Procedure

Guanidine hydrochloride (47.77 g, 0.5 mol) was added portionwise to a stirred suspension of sodium methoxide (32.42 g, 0.60 mol) in n-butanol (450 ml) at ambient temperature over 0.5 hour. After a further 0.5 hour a solution of methyl anthranilate (15 g, 0.10 mol) in n-butanol (150 ml) was added dropwise and then slowly brought to reflux. After distilling off ca. 100 ml of solvent the reaction mixture was heated under reflux at 116° for 117 hours. The cooled suspension was filtered, excess solvent removed and the residue dissolved in water, acidified to pH 5 and extracted with diethyl ether. The aqueous suspension was reacidified to pH 5, filtered off, washed with water and dried. The solid was then triturated in methanol, filtered, washed with ether and dried to give 2-amino-4-(3H)-quinazolone (3.0 g, 19%) m.p. >300°.

Workup

  1. temperatureto reflux
  2. distillationAfter distilling off ca. 100 ml of solvent the reaction mixture
  3. temperaturewas heated
  4. temperatureunder reflux at 116° for 117 hours
  5. filtrationThe cooled suspension was filtered
  6. customexcess solvent removed
  7. dissolutionthe residue dissolved in water
  8. extractionextracted with diethyl ether
  9. filtrationfiltered off
  10. washwashed with water
  11. customdried
  12. customThe solid was then triturated in methanol
  13. filtrationfiltered
  14. washwashed with ether
  15. customdried

Sources & evidence

ORD record
ord-ea48e4958f46471699ab44fe246c00a5
Source dataset
uspto-grants-1991_11
Patent number
US05064833

Reaction notes

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