Other Displacement Reactions of Nuclear Halogenoquinoxalines

Several minor displacement reactions of halogenoquinoxalines are illustrated in the following examples. [Pg.168]

3-Dichloroquinoxalme (191) and isopropyl 2-lithio-2-methoxy-2-( 1-methoxy-l-methylethoxy)acetate (192) (prepared in situ) gave the mixed ketal intermediate (194) that underwent gentle acid hydrolysis to afford 2-chloro-3-propoxyoxaloquinoxaline (193) [THF-(Me2NO)3PO, —78°C 20°C then 2M HCl, 25°C, 20 min 90%]. [Pg.169]

2-Iodoquinoxaline (195) gave 2-nitroquinoxahne (196) (AgN02, B114NF, Me2SO, 65°C, 3.5 h 44% after separation from a little 2(lf/)-quinoxali-none) treatment of 2-chloroquinoxaline with sodium nitrite gave a very poor yield of product (196). [Pg.169]

2-Iodo-3-methylquinoxaline (197, R = Me) gave 2-methyl-3-thiocyanatoqui-noxaline (198, R = Me) (KSCN, MeCN, reflux, 2h 80%) 3-iodo-2-quinoxalinecarbaldehyde (197, R = CHO) likewise gave 3-thiocyanato-2-quinoxalinecarbaldehyde (198, R = CHO) (KSCN, trace H2O, MeCN, reflux. [Pg.169]

2-Chloroquinoxaline (199) gave a separable mixture of 2-thiocyanatoquinoxa-line (200) and 2-isothiocycanatoquinoxalme (201) (KSCN, AcOH, 20°C, 4h [Pg.170]

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