From a Benzene Substrate with Two or More Synthons

FROM A BENZENE SUBSTRATE WITH TWO OR MORE SYNTHONS 

This category of primary synthesis is extremely rare in the quinoxaline series, although a few examples have been reported in recent literature. Thus a mixture of neat 1,2-benzenediamine (331) and an excess of p-bromobenzaldehyde heated at 350°C for 5 min afforded (with aerial oxidation ) 2,3-bis(p-bromophenyl) quinoxaline (332) in 50% yield and analogs were made similarly but usually in poor to mediocre yield after separation from byproducts. In addition, an 

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