Abstract
2-substituted 1H-perimidines are readily prepared, in high yields, by refluxing a mixture of sodium pyrosulfite, an aldehyde, and 1, 8-diaminonaphthalene in aqueous ethanol or N, N-dimethylformamide. The method is of wide applicability except from araldehydes bearing a strong electron-withdrawing group (-CN, -NO2).