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Cyclization and a rearrangement in concentrated sulfuric acid of 2-(4-substituted-phenyl)propylidenemalonodinitriles ( 1 ) into 1-amino-4-methyl-6-substituted-naphthalene-2-carbonitriles ( 5 ) appears to involve a series of steps such as ipso electrophilic attack of the protonated nitrile function on the para position of the phenyl group, opening of a spirobenzenium cation or its transformation, and ring reclosure to the naphthalene framework with participation of the secondary alkyl carbocation as an active electrophile.

Cyclization and a rearrangement in concentrated sulfuric acid of 2-(4-substituted-phenyl)propylidenemalonodinitriles ( 1 ) into 1-amino-4-methyl-6-substituted-naphthalene-2-carbonitriles ( 5 ) appears to involve a series of steps such as ipso electrophilic attack of the protonated nitrile function on the para position of the phenyl group, opening of a spirobenzenium cation or its transformation, and ring reclosure to the naphthalene framework with participation of the secondary alkyl carbocation as an active electrophile.

The study has been carried out to evaluate the feasibility of synthesis of 1-methyl-, 2-methyl-, 1,2-dimethyl-, and 1-ethyl-2-methylphenanthrene through the annulation of the naphthalene system with the exploitation of the dicyanovinyl moiety of 2-naphthylalkylidenemalonodinitriles as an active electrophile in cold solutions of concentrated sulfuric acid. 2-(2-Naphthyl)propanal ( 3 ), 1-(2-naphthyl)propan-2-one ( 9 ), 3-(2-naphthyl)butan-2-one ( 14 ), and 3-(2-naphthyl)pentan-2-one ( 19 ) had been condensed with malonodinitrile to afford 2-naphthylalkylidenemalonodinitriles which were then cyclised to give 4-amino-1-methylphenanthrene-3-carbonitrile ( 5 ), 4-amino-2-methylphenanthrene-3-carbonitrile ( 11 ), 4-amino-1,2-dimethylphenanthrene-3-carbonitrile ( 16 ), and 4-amino-1-ethyl-2-metylphenanthrene-3-carbonitrile ( 21 ). The nitrile function has been removed from the aminonitriles, with the exception of 21 , through hydrolysis and decarboxylation in alkaline ethanolic solutions under elevated pressure (∼3 MPa) and temperature 220–230°C to give the respective 4-amino-methylphenanthrenes. Diazotisation of the phenanthreneamines and the reaction with hypophosphorus acid has lead to the methylphenanthrenes in moderate yields (50–52%).

A synthesis of a variety of 5'-amino- m -terphenyls ( 6 ) and 3,5-diarylaminobenzenes through an efficient elimination of cyano groups from 5'-amino-4',6'-dicyano- m -terphenyls ( 4 ) using sodium hydroxide in ethanol at 220°, is described, The starting o-aminonitriles ( 4 ) are conveniently prepared from arylidenemalonodinitriles ( 1 ) and 1-arylethylidenemalonodinitriles ( 2 ). This strategy is applied for the synthesis of an aminoquaterphenyl ( 13 ) and a diaminoquinquephenyl ( 16 ).

Substitution d'un chlore par un groupe tosyl par reaction de methyl-2(phenyl-2-, t-butyl-2-) dichloro-3,3 acrylonitriles avec le p-toluenesulfinate de sodium