O-Phenylenediamine → 2(1H)-Quinoxalinone

HRID 751276Notes

Reaction equation

HRID 751276 reaction equation
[C:1]1([NH2:8])[C:2]([NH2:7])=[CH:3][CH:4]=[CH:5][CH:6]=1.[CH2:9]([O:11]C(=O)C=O)[CH3:10]>C(O)C>[NH:7]1[C:2]2[C:1](=[CH:6][CH:5]=[CH:4][CH:3]=2)[N:8]=[CH:10][C:9]1=[O:11]

Participants

4

Reactant 2

HCID 7243O-PhenylenediamineHCID 70211Ethyl oxoacetate

Product 1

HCID 145262(1H)-Quinoxalinone

Reagents, catalysts & solvents 1

HCID 702EthanolSolvent

Procedure

Heat benzene-1,2-diamine (7.5 g, 69 mmol) and oxo-acetic acid ethyl ester (20 mL) in ethanol (100 mL) at 120° C. for 18 h. Cool, filter the resulting precipitate, and wash with dry ether to give 1H-quinoxalin-2-one (6.7 g). Dissolve 1H-quinoxalin-2-one in acetic acid (300 mL), add bromine (5 mL), and stir the reaction mixture for 1 h. Filter the resulting crystals and wash with ether to afford 7-bromo-1H-quinoxalin-2-one (7.2 g). Reflux 7-bromo-1H-quinoxalin-2-one in POCl3 (30 mL) for 18 h. Remove POCl3 in vacuo, dissolve the product in 3:1 chloroform/isopropyl alcohol, and wash the organic phase with saturated sodium bicarbonate. Dry over sodium sulfate and purify by silica gel flash chromatography eluting with dichloromethane to 10% methanol/90% dichloromethane to afford the title compound as a yellow solid (4.5 g, 58%). MS (electrospray, m/z) 243.0 and 245.0 (M+1).

Workup

  1. temperatureCool
  2. filtrationfilter the resulting precipitate
  3. washwash with dry ether

Sources & evidence

ORD record
ord-52ab16490bef45b28ca6c0b666d6be60
Source dataset
uspto-grants-2008_07
Patent number
US07405299B2

Reaction notes

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