Urea → 8-Bromoquinazoline-2,4(1H,3H)-dione

HRID 1056276Notes

Reaction equation

HRID 1056276 reaction equation
[NH2:1][C:2]([NH2:4])=[O:3].N[C:6]1[C:14]([Br:15])=[CH:13][CH:12]=[CH:11][C:7]=1[C:8](O)=[O:9]>O>[Br:15][C:14]1[CH:13]=[CH:12][CH:11]=[C:7]2[C:6]=1[NH:4][C:2](=[O:3])[NH:1][C:8]2=[O:9]

Participants

4

Reactant 2

HCID 1176Urea2×HCID 2702592-Amino-3-bromobenzoic acid

Product 1

HCID 224576608-Bromoquinazoline-2,4(1H,3H)-dioneYield 96.3%

Reagents, catalysts & solvents 1

HCID 962WaterSolvent2×

Conditions

Temperature
170 °C

Procedure

Urea (Sigma; 3.78 g, 63.0 mmol) and 2-amino-3-bromo-benzoic acid (Aldrich; 4.00 g, 18.52 mmol) were combined and heated, open to air, in a 170° C. oil bath. After 3 h, additional urea (Sigma; 3.78 g, 63.0 mmol) was added and stirring continued. After 5 h, the reaction was judged complete and cooled, treated with water, filtered, and the solid dried overnight in vacuo to give 4.7 g. The material was treated with water and stirred rapidly for 3 h to give a fine suspension. The solid was collected by filtration and dried in vacuo overnight, to give 8-bromoquinazoline-2,4(1H,3H)-dione (4.30 g, 17.84 mmol, 96% yield) as a light yellow solid. 1H NMR (400 MHz, DMSO-d6) δ ppm 11.50 (1H, br. s.), 10.25 (1H, br. s.), 7.93 (2H, dq, J=7.8, 1.4 Hz), 7.13 (1H, t, J=7.8 Hz). m/z (ESI, +ve ion) 240.9/242.9 (M+H)+.

Workup

  1. waitAfter 5 h
  2. temperaturecooled
  3. filtrationfiltered
  4. customthe solid dried overnight in vacuo
  5. customto give 4.7 g
  6. stirringstirred rapidly for 3 h
  7. customto give a fine suspension
  8. filtrationThe solid was collected by filtration
  9. customdried in vacuo overnight

Sources & evidence

ORD record
ord-8ef156da78de4d5c82b2de2decf05ae4
Source dataset
uspto-grants-2016_07
Patent number
US09394297B2

Reaction notes

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