Cyclization Reactions of Extranuclear Halogenoquinoxalines

Most of the recently reported cyclizations of extranuclear halogenoquinoxalines have involved 2,3- or 6,7-bis(halogenoalkyl)quinoxalines as substrates. These and a few other types of cyclization are illustrated briefly in the following examples. [Pg.186]

Ethyl 3-dichloromethyl-2-quinoxalinecarboxylate 1,4-dioxide (292) gave pyri-dazino[4,5-/7]quinoxalin-l(2/i)-one (293) (H2NNH2-H20, EtOH, 0°C 20°C, 24 h 60% note the concomitant removal of the A(-oxide entities). [Pg.186]

3-Bis[m-(bromomethyl)phenyl]quinoxalLne (294) gave 1 l,12-dihydro-6,10 13,17-dimethylenecyclotetradeca[fo]quinoxalLne (295) (PhLi, THF-PhH- [Pg.187]

7-Bis(bromomethyl)quinoxaline (296) gave either 6,8-dihydrofuro[3,4-g]qui-noxaline (297) (NaOH, H20-MeCN, BU4NHSO4, no further details 84%) or ethyl 7-isocyano-7,8-dihydro-6//-cyclopenta[g]quinoxaline-7-carboxylate (298) (Et02CCH2NC, K2CO3, BU4NHSO4, MeCN, no further details 38%) and thence the 7-amino ester (HCl-EtOH, no further details 90%). [Pg.187]

2-Dibromo-3,3-diethoxyprop-l-enyl)quinoxaline (302) and disodium trithio-carbonate gave 2-(diethoxymethyl)thieno[2,3- ]quinoxaline (303) (MeOH- [Pg.188]

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