Phosphorus oxychloride → 2-Chloro-5,6-dihydro-4H-imidazo[1,5,4-de]quinoxaline
Reaction equation
[NH:1]1[C:11]2[C:12]3[N:3]([CH2:4][CH2:5][NH:6][C:7]=3[CH:8]=[CH:9][CH:10]=2)[C:2]1=O.P(Cl)(Cl)([Cl:16])=O>>[Cl:16][C:2]1[N:3]2[CH2:4][CH2:5][NH:6][C:7]3[CH:8]=[CH:9][CH:10]=[C:11]([C:12]=32)[N:1]=1Participants
3
Procedure
3 g (0.0155 mol) of 5,6-dihydro-4H-imidazo[1,5,4-de]quinoxalin-2(1H)-one in 60 ml of phosphoryl chloride are heated at the reflux temperature for 3 hours. The solvent is evaporated to dryness and the residue taken up successively in ice-cold water and in a concentrated aqueous ammonia solution. Extraction is then carried out twice with ether and the organic phases are combined, dried and evaporated to dryness. The residue is purified by chromatography on a column of silica gel, the eluent being ether. There are obtained 1.8 g of product in the oil form which is used as is in the following stage.
Workup
- customThe solvent is evaporated to dryness