Hydrochloric Acid → 6,7-Dichloroquinazoline-2,4(1H,3H)-dione

HRID 40763Notes

Reaction equation

HRID 40763 reaction equation
[NH2:1][C:2]1[CH:10]=[C:9]([Cl:11])[C:8]([Cl:12])=[CH:7][C:3]=1[C:4](O)=[O:5].[NH2:13][C:14](N)=[O:15].[OH-].[Na+].Cl>O>[Cl:12][C:8]1[CH:7]=[C:3]2[C:2](=[CH:10][C:9]=1[Cl:11])[NH:1][C:14](=[O:15])[NH:13][C:4]2=[O:5]

Participants

6

Reactant 4

HCID 313Hydrochloric AcidHCID 1176UreaHCID 14798Sodium HydroxideHCID 121045502-Amino-4,5-dichlorobenzoic acid

Product 1

HCID 196042516,7-Dichloroquinazoline-2,4(1H,3H)-dioneYield 96.3%

Reagents, catalysts & solvents 1

HCID 962WaterSolvent2×

Conditions

Temperature
100 °C

Procedure

2-Amino-4,5-dichlorobenzoic acid (920 mg) and urea (2.75 g) were stirred at 160° C. After 6 hours the mixture was cooled to 100° C. and an equivalent volume of water was added while stirring was continued for 5 minutes. The formed precipitate was filtered off and washed with water to yield a solid cake that was suspended in a solution of 0.5 N NaOH in water. The suspension was heated to boil for 5 minutes and then cooled to r.t. The pH was adjusted to about 2 with HCl and the quinazoline-dione was filtered off. After washing with a mixture of water and methanol the product was dried in vacuo to yield 994 mg (94%) of a solid. 1H-NMR (DMSO-δ6) δ (ppm) 7.89 (s, 1H), 7.33 (s, 1H).

Workup

  1. filtrationThe formed precipitate was filtered off
  2. washwashed with water
  3. customto yield a solid cake that
  4. temperatureThe suspension was heated
  5. waitto boil for 5 minutes
  6. temperaturecooled to r.t
  7. filtrationthe quinazoline-dione was filtered off
  8. washAfter washing with a mixture of water and methanol the product
  9. customwas dried in vacuo

Sources & evidence

ORD record
ord-8aae655873774752bc8683515b1af7f7
Source dataset
uspto-grants-2013_09
Patent number
US08530486B2

Reaction notes

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