PROCEDIMIENTO PARA LA OBTENCION DE BENZOFURANOS.

摘要

1315536 Triazolylphenylbenzofurans CIBA GEIGY AG 26 June 1970 [27 June 1969] 31164/70 Heading C2C [Also in Divisions C3 C4 C5 and D1] The invention comprises compounds (I), where R 1 is hydrogen or C 1-6 alkyl; and R 2 is hydrogen, halogen, C 1-6 alkyl or alkoxy, carboxy carbalkoxy, aminocarbonyl, mono- or di-alkylaminocarbonyl, sulpho, alkylsulphonyl, alkoxysulphonyl, aminosulphonyl, mono- or dialkylaminosulphonyl, or phenyl or, R 1 and R 2 form an annularly-linked benzene ring; R 3 is H or C 1-6 alkyl or alkoxy; and R 4 is hydrogen, halogen or C 1-6 alkyl or, R 3 and R 4 form an annularlylinked benzene ring; R 5 is hydrogen, C 1-6 alkyl or optionally substituted phenyl; X is a group of formula P, Q or R, where the phenylene group A is optionally substituted in the 4- and/or 5-position by C 1-6 alkyl or alkoxy, and the napthylene-1,2 group B is optionally substituted by a sulpho or dialkylaminosulphonyl group and their preparation by diazotizing compounds (II) and coupling the resulting diazo compound with a ketone Z-CH 2 -CO-Y or Z-CO-CH 2 -Y, where Y is phenyl and Z is methyl, reacting the azo-compound with hydroxylamine; oxidatively ring closing the oxime hydrazone and treating the resulting v-triazole- 1-oxide with a reducing agent to give a compound (I) where X is a group of Formula P or coupling the diazo-compound with an optionally substituted aniline or naphthylamine (in the O-position to the amino group) and converting the resulting azo-amine with an oxidizing agent, into a compound (I) where X is a group of Formula Q or R. Aminophenylbenzofurans (II) where R 5 is hydrogen may be made by the appropriate salicylaldehyde with the appropriate p-nitrobenzyl chloride, cyclizing the resulting 2 - (41 - nitrobenzyloxy)benzaldehyde and reducing the so produced 2-(41-nitrophenyl)- benzofuran; or by reacting, e.g. when R 5 is methyl, the appropriate o-hydroxyacetophenone with the appropriate p-nitrobenzyl chloride, cyclizing the resulting 2-(41-nitrobenzyloxy)- acetophenone to give the 2-(41-nitrophenyl)-3- methylbenzofuran which is reduced. Aminophenylbenzofurans (II) when R 5 is a group other than methyl are made similarly.