Patent GB-833859-A (GB)
Title: ªÏ-aldehydes of n-substituted ªÏ-cyanomethylene indoline derivatives
IPC: C07D209/18
Filed: 1958-05-22
Abstract: The invention comprises o -aldehydes of N-substituted o -cyanomethylene indoline derivatives of formula <FORM:0833859/IV (b)/1> wherein A is a naphthylene radical or a phenylene radical substituted in the 5- or 6-positions by hydrogen, chlorine, bromine, methoxy, ethoxy, methylmercapto, ethylmercapto, phenyl, nitro or NR1R2 groups, R1 and R2 being hydrogen, methyl, ethyl, propyl, butyl, ethanolyl, chloroethyl or cyanoethyl, X is a carbon atom dialkylated with methyl, ethyl, propyl or butyl radicals, Y is a mono-substituted nitrogen atom, the substituent being a saturated straight- or branched-chain alkyl radical containing up to 18 carbon atoms, or a phenyl radical, Z is hydrogen or a nitrile group and n is 0 or 1. They may be prepared by reacting an o -cyanomethylene indoline derivative of formula <FORM:0833859/IV (b)/2> with an N-substituted formic acid amide, the substituents of which contain a total of not more than 10 carbon atoms, in the presence of an inorganic acid chloride such as phosphorus oxychloride, phosgene, thionyl chloride or sulphuryl chloride.  Many o -cyanomethylene indolines suitable as starting materials and the o -aldehydes obtainable therefrom are specified.  Specified N-disubstituted formic acid amides comprise N,N-di(C1-5 alkyl) formamides and N-(C1-4 alkyl) formanilides. Chlorinated hydrocarbons such as chlorobenzene and o-dichlorobenzene or an excess of the formylizing agent or of the condensing agent may be used as solvent.  The reaction temperature is generally 0-120 DEG C.  The products may be condensed with aromatic amines to give azomethine dyes (see Group IV (c)). Examples describe the preparation of the o -aldehydes of 1,3,3-trimethyl-2-cyanomethylene-indoline, 1,3,3,5 -tetramethyl - 2 - cyanomethylene - indoline, 1,3,3-trimethyl-2-(a ,g -dicyanopropenylidene)-indoline, 1,3,3-trimethyl-5-methoxy -2-cyanomethylene-indoline, 1,3,3-trimethyl -5-chloro-2-cyanomethylene-indoline and 1,3,3-trimethyl-2-(o -cyanopropenylidene) -indoline, using methylformanilide or dimethylformamide with phosphorus oxychloride.ALSO:The invention comprises o -aldehydes of N-substituted o -cyanomethylene indoline derivatives of formula <FORM:0833859/IV(c)/1> wherein A is a naphthylene radical or a phenylene radical substituted in the 5- and 6-positions by hydrogen, chlorine, bromine, methoxy, ethoxy, methylmercapto, ethylmercapto, phenyl, nitro or NR1R2 groups, R1 and R2 being hydrogen, methyl, ethyl, propyl, butyl, ethanolyl, chloroethyl or cyanoethyl, X is a carbon atom dialkylated with methyl, ethyl, propyl or butyl radicals, Y is a monosubstituted nitrogen atom, the substituent being a saturated straight- or branched-chain alkyl radical containing up to 18 carbon atoms, or a phenyl radical, Z is hydrogen or a nitrile group and n is 0 or 1. They may be prepared by reacting an o -cyanomethylene indolene derivative of formula <FORM:0833859/IV(c)/2> with an N-disubstituted formic acid amide, the substituents of which contain a total of not more than 10 carbon atoms, in the presence of an inorganic chloride such as phosphorus oxychloride, phosgene, thionyl chloride or sulphyryl chloride.  Many o -cyanomethylene indolines suitable as starting materials and the o -aldehydes obtainable therefrom are specified.  Specified N-disubstituted formic acid amides comprise N,N-di-(C1-5-alkyl)-formamides and N - (C1-4 - alkyl) - formanilides. Chlorinated hydrocarbons such as chlorobenzene and o-dichlorobenzene or an excess of the formylizing agent or of the condensing agent may be used as solvent.  The reaction temperature is generally 0-120 DEG C.  The products may be condensed with aromatic amines to give azomethine dyes, e.g. an orange dye suitable as a filter dyestuff may be obtained by reacting 1,3,3-trimethyl-2-cyanomethylene indoline - o - aldehyde with p-phenetidine.  Examples describe the preparation of the o -aldehydes of 1,3,3-trimethyl-2-cyanomethylene-indoline, 1,3,3,5-tetramethyl-2 - cyanomethylene - indoline, 1,3,3 - trimethyl-2 - (a ,g  - dicyanopropenylidene) - indoline, 1,3,3-trimethyl - 5 - methoxy - 2 - cyanomethylene - indoline, 1,3,3 - trimethyl - 5 - chloro - 2 - cyanomethylene-indoline and 1,3,3-trimethyl-2-(o -cyanopropenylidene)-indoline, using methylformanilide or dimethylformamide with phosphorus oxychloride.