Reactions of Extranuclear Hydroxyquinoxalines

Extranuclear hydroxyquinoxalines react as do regular alcohols or phenols. Examples of theii conversion into alkylquinoxalines (Section 2.2.1.5) ox conversion into extranuclear halogenoquinoxalines (Section 3.3) have been given already. Other reactions are illustrated by the following classihed examples. 

2-(a-Hydroxybenzyl)-3-phenylquinoxaline (170, R = H) gave 2-(a-acetoxy-benzyl)-3-phenylquinoxaIine (170, R = Ac) (neat AC2O, reflux, 6 h  

3-[2-Hydroxy-l-(phenyIhydrazono)ethyl]-2(17/)-quinoxalinone (172, R = H) gave 3-[2-acetoxy-l-(phenyUiydrazono)ethyl]-2(l//)-quinoxalinone (172, R = Ac) (AC2O, pyridine, 20°C, 24 h 95%) the analogous 3-[2,3,4-triacetoxy-l-(naphthalen-2-ylhydrazono)butyl]-2(l//)-quinoxalinone (97%) was made 

3-Bis(hydroxymethyl)quinoxaline 1,4-dioxide (dioxidine 173, R = H) and methyl isocyanate gave 2,3-bis(A(-methylcarbamoyloxymethyl)quinoxaline 1,4-dioxide (173, R = CONHMe) (for details, see original). 

1-Methyl-3-(2,3,4-trihydroxy-1-phenylhydrazonobutyl)-2(l/7)-quinoxalinone (175) gave 3-[a-formyl-a-(phenylhydrazono)methyl]-1 -methyl-2( 1 H)-qm-noxalinone (176) (NalOa, H2O, 20°C, 2h 90%) ° analogs like 3-[a-(m-fluorophenylhydrazono)-a-formyhnethyl]- (177, R = m-F) (80%) and 3-[a-formyl-a-(p-nitrophenylhydrazono)methyl]-2(l//)-quinoxalinone (177, R = 

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