GB698070A - New intermediate products for the phthalocyanine synthesis - Google Patents

Abstract

The invention comprises compounds of the formula <FORM:0698070/IV (b)/1> where A is an o-arylene radical (substituted or not) and R is an alkyl, hydroxyalkyl or alkoxyalkyl radical of 1-6 carbon atoms or a cycloalkyl radical. These are made by reacting o-arylene dinitriles with alkali alcoholates or substances reacting as such, in an alcohol or mixture therewith with other solvents; the crystalline products, often containing one extra molecule of alcohol, precipitate during the reaction or after cooling. Preferably one mol. or more of alcoholate is used per mol. of dinitrile. Liquid ammonia is a suitable solvent for mixture with the alcohol. The presence of water leads to the formation of imino-dicarboxylic acid imides. The products of the invention, in the free state or as their alkali salts, are intermediates for amino-imino-isoindolenines (see Specification 698,049), dehydro-phthalocyanines and phthalocyanines (see Specification 698,039). In the examples phthalonitrile is reacted with methanol, ethanol, isopropanol and ethylene glycol to give products where A is a benzene nucleus and R is methyl, ethyl, isopropyl and b -hydroxyethyl respectively. Other suitable alcohols are n-propanol, n- and iso-butanol, hexanol, cyclohexanol, propylene and butylene glycols and glycerol. The phthalonitrile may be substituted by halogen, methyl, t-butyl, phenyl, alkoxy, phenoxy, alkylthio, arylthio or sulphonic acid groups. 2 : 3-Dicyanonaphthalene and 2 : 3-dicyanopyridine are also suitable and in general all dinitriles known to be used for the preparation of phthalocyanines.