The cyclocondensations of benzofuroxan 1a with carbonylcompounds were smoothly and efficiently carried out by the adsorption of the components on the surface of silica gel or a molecular sieve to form a 2,3-disubstituted quinoxaline 1,4-dioxide. When the reactions using a molecular sieve 3A (powder) were carried out at 90°, the actual reaction times were reduced to 0.5-2 hours. Although Duerckheimer
Reactions of Benzofuroxan with 1,3-Diketones or β-Ketoesters on Silica Gel or Alumina
作者:Minoru Hasegawa、Tohru Takabatake
DOI:10.1055/s-1985-31391
日期:——
The cyclocondensation of benzofuroxan with 1,3-diketones, 3-oxoalkanoic esters, butanedioic esters, or 3-oxoalkanamides in the presence of silica gel (adsorption of the components on silica gel) represents a convenient method for the synthesis of 2,3-disubstituted quinoxaline-1,4-bis-oxides.