Using a Diacyl Dihalide Oxalyl Halide or Related Synthon

Using a Diacyl Dihalide (Oxalyl Halide) or Related Synthon 

Like the preceding category, this is poorly represented in recent literature, although it has significant potential, as illustrated in the following examples. 

2-(2-Amino-2-carboxyethyl)amino-4,5-dimethylaniline and oxalyl chloride gave 1 -(2-amino-2-carboxyethyl)-6,7-dimethyl-2,3(l//,4//)-quinoxalinedione (297) as hydrochloride (CH2CI2, 0°C, 30 min then 20°C, 12 h then 30°C, 6 h 43%).  

5-Dimethyl-1,2-benzenediamine (298) and l,2-dichloro-l,2-bis(2,4-dichloro-phenylhydrazono)ethane (299) gave 2,3-bis[AF-(2,4-dichloeophenyl)hydra-zino]-6,7-dimethylquinoxaline (300) (Et3N, EtOH, reflux, 3 h 90%), which was oxidized subsequently to afford 2,4-bis(2,4-dichlorophenylazo)-6,7-dimethylquinoxaline (301) [(Fe3CC02)2lPh, CH2CI2, 20°C, 2 h 81%].  

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