Patent GB-656472-A (GB)
Title: Manufacture of new imidazolines
Filed: 1948-01-30
Abstract: 2-(N : N-Diphenylaminomethyl)-imidazolines, or salts thereof, which compounds are substituted in meta- and/or para-position only of one or both the phenyl radicals at least one of said substituents being an unsubstituted or etherified nuclear hydroxyl group, are prepared by heating a 2-oxymethyl-imidazoline ester of a hydrohalic acid or an alkyl or aryl sulphonic acid or a salt of such ester with a diphenylamine which is substituted in meta- and/or para-position only of one or both of the phenyl radicals, at least one of the substituents being an unsubstituted, etherified or esterified hydroxyl group or with an N-metal derivative of a diphenylamine which is substituted as specified except by a free hydroxyl group.  The further substituents may be alkyl radicals, e.g. methyl, ethyl or propyl radicals.  The imidazoline residue may also contain substituents, e.g. alkyl radicals such as methyl, ethyl or propyl radicals.  The hydroxy groups may be etherified with an aliphatic alcohol, e.g. methyl or ethyl alcohol.  In the case of an esterified hydroxyl group hydrolysis to the free hydroxyl group takes place during the process.  The imidazolines are also prepared by heating an N : N-diphenylamino-acetic acid which is substituted in meta- and/or para-position only of one or both of the phenyl radicals at least one of the substituents being an unsubstituted, etherified or esterified nuclear hydroxyl group, or an imido-ether, imido-halide, thioamide, thioimido-ether, amide, ester, halide, amidine or nitrile of such acid, with an alkylene diamine in which the amino groups are bound to vicinal carbon atoms and are unsubstituted, or a salt thereof, or with ethylene urea.  The alkylene diamines may be substituted on the carbon atoms, e.g. by an alkyl group such as a methyl or ethyl group. The acid derivatives of the diphenylamino acetic acid may be formed during the course of the reaction, e.g. by using a nitrile in the presence of hydrogen sulphide while the hydrogen sulphide may be formed from a compound forming hydrogen sulphide.  The alkylene diamine may be a 1 : 2-diamine acylated with an N : N-diphenylamino-acetic acid specified above and the desired imidazoline is obtained by splitting out water.  Salts of the desired imidazolines may be converted in the free bases, or the desired imidazolines may be converted into salts.  A number of detailed examples are given.  Specifications 528,915 and 529,054 are referred to.  N-(p-Methoxy-phenyl)-N-phenylaminoacetonitrile is obtained by the condensation of p-methoxy-diphenylamine with formaldehyde and hydrocyanic acid in glacial acetic acid.  It can be converted into the corresponding imido ether by treatment with an alcohol and a hydrohalic acid in an inert diluent. N-(p-Methoxy-phenyl)-N-phenylamino-acetamidine is prepared by reacting the imido ether referred to in the previous paragraph with ammonia.  N-(p-Methyl-phenyl)-m-acetoxyphenylamine is prepared by reacting the sodium salt of N-(p-methyl-phenyl)-m-oxyphenylamine and acetyl chloride. N-(p-Methyl-phenyl)-N-(m-acetoxy-phenyl)-amino-acetonitrile is prepared by reacting N-(p-methyl-phenyl)-m-acetoxyphenylamine with paraformaldehyde and potassium cyanide. N-(p-Methyl-phenyl)-N-(m-oxyphenyl)-amino-acetonitrile is prepared by the mild alkaline hydrolysis of the corresponding aminoacetonitrile having a m-acetoxyphenyl radical.  The Specification as open to inspection under Sect. 91 refers to the above process wherein the diphenylamine or the N : N-diphenyl-amino-alkane carboxylic or derivative contains at least one substituted or unsubstituted hydroxyl group in any position of the phenyl radicals.  This subject-matter does not appear in the Specification as accepted.