Quinoxalinols from a-keto acids

Compounds with keto groups often give more than one derivative on silylation, acylation or esterification because of the possibility of geometrical isomerism, and yields may be unsatisfactory. For oc-keto acids the fonna- 

The quinoxalinols may be analysed by TLC or HPLC, and are UV-absorbing and fluorescent [89]. For gas chromatogrphy silylation is necessary [86, 90]. Electron capturing derivatives have been made using p-chloro-, 4,5-dichloro- and 3,4,5,6-tetrafluoro-l,2-phenylenedia-mines [84]. 

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