Benzyl mercaptan → HCID 118094025, compound

Reaction equation

[CH2:1]([SH:8])[C:2]1[CH:7]=[CH:6][CH:5]=[CH:4][CH:3]=1.Br[C:10]1[CH:19]=[C:18]([Cl:20])[CH:17]=[C:16]2[C:11]=1[N:12]=[CH:13][CH:14]=[N:15]2.C(=O)([O-])[O-].[Cs+].[Cs+]>CN(C=O)C>[CH2:1]([S:8][C:10]1[CH:19]=[C:18]([Cl:20])[CH:17]=[C:16]2[C:11]=1[N:12]=[CH:13][CH:14]=[N:15]2)[C:2]1[CH:7]=[CH:6][CH:5]=[CH:4][CH:3]=1

Participants

Procedure

Benzyl mercaptan (0.51 g, 4.1 mmol) was added dropwise to a mixture of 5-bromo-7-chloroquinoxaline (1 g, 4.1 mmol), cesium carbonate (1.6 g, 4.92 mmol) at 0° C. in DMF (25 ml) under nitrogen. The reaction mixture was allowed to warm to room temperature, stirred for 2 hours and partitioned between ethyl acetate and water. The organic phase was washed with brine, dried with sodium sulfate and concentrated. Purification by column chromatography gave 5-(benzylthio)-7-chloroquinoxaline (rf=0.39 in 9:1 hexanes/ethyl acetate) as a yellow solid. The undesired regioisomer elutes afterwards (rf=0.27 in 9:1 hexanes/ethyl acetate).