Anthraquinone and anthrone series. XXII . 3:4:9:10 - Dibenzopyrene and pentaphene from indanthrene scarlet 4G and Mayvat brilliant red AF

Abstract

Mayvat brilliant red AF has been identified as a halogenated derivative of 3:4:9:10-dibenzopyrene-5:8-quinone (II), the latter being obtained by dehalogenation of Mayvat brilliant red AF or Indanthrene scarlet 4G with Raney nickel, aqueous sodium hydroxide and hydrogen. Reduction of (II) with aluminium tricyclohexoxide gave 3:4:9:10-dibenzopyrene (I), a potent carcinogen, which was isolated by Bonnet and Neukomm from tobacco smoke. Oxidation of 3:4:9:10-dibenzopyrene-5:8-quinone with chromic acid in glacial acetic acid gave pentaphene-5:14:8:13-diquinone (V). Reduction of (V) with aluminium tricyclohexoxide yielded pentaphene (VI). Condensation of (V) with hydrazine gave 1:2-diaza-3:4:9:10-dibenzopyrene-5:8-quinone (VII), reduction of which with aluminium tricyclohexoxide gave 1:2-diaza-3:4:9:10-dibenzopyrene (VIII).