Patent GB-730467-A (GB)
Title: New dyestuff intermediates
Inventor: FRANCE HAROLD
IPC: C07D209/50
Filed: 1951-12-28
Abstract: Tetra - aza - porphin colouring - matters are manufactured by heating, in the presence or absence of metals, intermediates having in one tautomeric form the formula <FORM:0730467/IV (c)/1> or <FORM:0730467/IV (c)/2> wherein X represents an amino, alkyloxy, aralkyloxy or cycloalkyloxy group and wherein the alkyl, aralkyl or cycloalkyl radicals may carry substituents, R1 and R2 represent hydrogen or alkyl, aralkyl or cycloalkyl groups or jointly form with the 3 : 4-double bond of the pyrrole or isopyrrole nucleus a cyclohexene ring, R3 represents atoms which complete a heterocyclic ring, and n is a number greater than zero.  In examples: (1) 2-imino-5-amino-3 : 4-tetrahydrobenzisopyrrole turns pink when heated to 110 DEG  C. and progressively darkens on further heating; (2) 2-imino-5-amino-3 : 4-dimethylisopyrrole turns dark purple on heating above 135 DEG  C.; (3) the hydrochloride of 2-imino - 5 - b  - hydroxyethoxy - 3 : 4 - tetrahydrobenzisopyrrole (tautomeric with 2 : 2-ethylenedioxy - 5 - amino - 3 : 4 - tetrahydrobenzisopyrrole) is heated with triethylamine in o-dichlorobenzene to produce hexadecahydrophthalocyanine; (5) a compound of the first formula above in which X=CH3O and R1+R2=(CH2)4 is boiled in o-dichlorobenzene, or in n-propanol containing nickel acetate, yielding respectively hexadecahydrophthalocyanine and its nickel compound.ALSO:The invention comprises new dyestuff intermediates having in one tautomeric form the formula: <FORM:0730467/IV (b)/1> or <FORM:0730467/IV (b)/2> wherein X=amino, alkyloxy, aralkyloxy or cycloalkyloxy, and wherein the alkyl, aralkyl or cycloalkyl radicals may carry substituents (e.g. heterocyclic, alkyloxy, amino, substituted amino or hydroxyl groups or halogen atoms), R1 and R2=hydrogen or alkyl, aralkyl or cycloalkyl groups, which may carry substituents, or may be joined together to form with the 3 : 4 double bond of the pyrrole or isopyrrole nucleus a cyclohexene ring, R3 represents atoms which complete a heterocyclic ring, and n=a number greater than zero, and the manufacture thereof by the following processes: (a) when X=alkyloxy-, aralkyloxy-, or cycloalkyloxy-, by treating a maleic or fumaric dinitrile, which may carry one or two alkyl, aralkyl or cycloalkyl radicals, or a D 1-tetrahydrophthalonitrile, with a compound which contains a hydroxyl group attached to an alkyl, aralkyl or cycloalkyl radical, in the presence of an ancillary compound of the general formula R-O-R1 (wherein R is an alkali metal, one equivalent of an alkaline-earth metal (including magnesium), or an onium radical, and R1 is hydrogen or an organic radical; (b) when X=amino, by treating the appropriate dinitrile with ammonia, optionally in the presence of an ancillary substance as defined above.  The products may be isolated in the form of salts, e.g. hydrochlorides, picrates or naphthalene mono-, di- or trisulphonates.  Examples describe the preparation of: (1) 2-imino-5-amino-3 : 4-tetrahydrobenz-isopyrrole from D 1-tetrahydrophthalonitrile and ammonia in a solution of sodium in methanol; (2) 2-imino-5-amino-3 : 4-dimethylisopyrrole similarly from dimethylfumaric dinitrile; (3) 5-b -hydroxyethoxy-2-imino-3 : 4-tetrahydrobenz-isopyrrole or the tautomeric 2 : 2 - ethylenedioxy - 5 - amino - 3 : 4 - tetrahydrobenzisopyrrole from D 1 - tetrahydrophthalonitrile and a solution of sodium in ethylene glycol; (4) 5-b -hydroxyethoxy-2-imino - 3 : 4 - dimethylisopyrrole or the tautomeric 2 : 2 - ethylenedioxy - 5 - amino-3 - 4 - dimethyl - isopyrrole similarly from dimethylfumaric dinitrile; (5) a compound of the first formula above in which X=CH3O and R1+R2=(CH2)4, from D 1-tetrahydrophthalonitrile and methanolic caustic soda. Additional starting materials specified are: ethanol; dimethylmaleic dinitrile, citraconic dinitrile.  Specification 698,049 is referred to.  The Provisional Specification comprises also compounds of the first general formula above in which X represents a substituted amino group (obtainable by using an amine in place of ammonia in method (b) above) or an alkylmercapto, aralkylmercapto or cycloalkylmercapto group (obtainable by using a mercaptan in place of an alcohol in method (a) above), and the alcohol or mercaptan addition products and metal complexes of the various compounds, and describes an alternative method of preparing the compounds in which X is an amino or substituted amino group by treating a compound in which X is alkyloxy, aralkyloxy or cycloalkyloxy, or an alcohol addition product thereof, with ammonia or an amine (e.g. aniline, methylamine or ethylamine).