Hydrolysis, Alcoholysis, or Phenolysis of Nuclear Halogenoquinoxalines

Note Perhaps because so many halogenoquinoxalines are themselves derived from quinoxahnones, the reverse process of hydrolysis is seldom reported the examples are all special cases in which a passenger group would complicate or preclude a straightforward acidic or alkaline hydrolysis. 

3-Chloro-2-quinoxalinecarbaldehyde oxime (125) gave 3-oxo-3,4-dihydro-2-quinoxalinecarbonitrile (126) (K2CO3, EtOH, reflux, 3 h 82%).  

7-Dichloro-3-[p-(l-ethoxycarbonylethyl)phenoxy]quinoxaline (127) gave 7-chloro-3- [p-( 1 -ethoxycarbonylethyl)phenoxy] -2( l//)-quinoxalinone (128), 

3-Bromo-5,6,7,8-tetrahydro-2-quinoxahnecarbonitrile (131) gave the 3-methoxy analog (132) (NaOH, MeOH, 20°C, 2h 90%) and thence 3-oxo-3,4,5,6,7,8-hexahydro-2-quinoxalmecarbonitrile (133) (Nal, MesSiCl, MeCN, 20°C, 6h 91%) this gentle indirect hydrolysis was clearly adopted to avoid hydrolysis of the nitrile group).  

Alcoholysis to Alkoxyquinoxalines Bearing No Functional Passenger Groups 

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