The surprising nucleophilic addition of aminochlorocarbenes to diethyl acetylenedicarboxylate and to oxalyl chloride: quinolines and benzo[1,4]diazepines from N-alkylformanilides and oxalyl chloride in the presence of Hünig's base.
Vilsmeier reagents derived from N-methylformanilides undergo ready deprotonation with Hünig's base. In xylene, the derived nucleophilic arylaminochlorocarbenes bearing 4-methyl- and 4-methoxy-substituents react with acetylenedicarboxylates to give 2-(2-chloro-1,2-bis(ethoxycarbonyl)vinyl)-3,4-bis(ethoxycarbonyl)-1-methyl-1,2-dihydroquinolines while most derivatives react with oxalyl chloride to give substituted 1-methyl-4 phenylbenzo[f][1,4]diazepine-2,3-dicarboxylic anhydrides.
Department of Chemistry, Beijing Normal University, Beijing 100875, China. yincheng@95777.com
Ying
Y
Cheng
Hua
H
Yang
Otto
O
Meth-Cohn