Hydrochloric Acid → 6-bromo-1-ethoxycarbonylmethylquinoxalin-2(1H)-one

HRID 373770Notes

Reaction equation

HRID 373770 reaction equation
[Br:1][C:2]1[CH:3]=[C:4]2[C:9](=[CH:10][CH:11]=1)[NH:8][C:7](=[O:12])[CH:6]=[N:5]2.[H-].[Na+].Br[CH2:16][C:17]([O:19][CH2:20][CH3:21])=[O:18].Cl>CN(C=O)C>[Br:1][C:2]1[CH:3]=[C:4]2[C:9](=[CH:10][CH:11]=1)[N:8]([CH2:16][C:17]([O:19][CH2:20][CH3:21])=[O:18])[C:7](=[O:12])[CH:6]=[N:5]2

Participants

6

Reactant 4

HCID 313Hydrochloric AcidHCID 7748Ethyl bromoacetateHCID 24758Sodium hydrideHCID 126863946-Bromo-1,2-dihydroquinoxalin-2-one

Product 1

HCID 198084496-bromo-1-ethoxycarbonylmethylquinoxalin-2(1H)-oneYield 80%

Reagents, catalysts & solvents 1

HCID 6228DimethylformamideSolvent

Procedure

Under a nitrogen atmosphere 6-bromoquinoxalin-2(1H)-one (2.03 g, 9 mmol) (J.Med.Chem., 24, (1981), 93) was dissolved in 22 ml of dry DMF and sodium hydride (0.44 g, 10.8 mmol (60% mineral oil dispersion)) was added. After stirring for 2 h, ethyl bromoacetate (1.25 ml, 11.3 mmol) was added and the mixture was stirred for 3.5 h. The reaction mixture was poured onto crushed ice and acidified (pH=4.5) by addition of dilute hydrochloric acid. The precipitate was filtered off, washed with water and air dried. The crude product (containing a minor fraction of O-alkylated product) was triturated with ether (100 ml), the precipitate filtered off, washed with ether and dried to afford 1.95 g (80%) of pure 6-bromo-1-ethoxycarbonylmethylquinoxalin-2(1H)-one. 1H-NMR (DMSO-d6):δ1.22 (t, 3H), 4.17 (q, 2H), 5.08 (s, 2H), 7.56 (d, 1H), 7.83 (dd, 1H), 8.09 (dd, 1H), 8.37 (s, 1H).

Workup

  1. stirringthe mixture was stirred for 3.5 h
  2. additionThe reaction mixture was poured
  3. customonto crushed ice
  4. filtrationThe precipitate was filtered off
  5. washwashed with water and air
  6. customdried
  7. additionThe crude product (containing a minor fraction of O-alkylated product)
  8. customwas triturated with ether (100 ml)
  9. filtrationthe precipitate filtered off
  10. washwashed with ether
  11. customdried

Sources & evidence

ORD record
ord-86a4749508af47d596394e0586be9092
Source dataset
uspto-grants-1992_11
Patent number
US05166155

Reaction notes

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