Patent GB-749826-A (GB)
Title: Manufacture of new complex chromium compounds of monoazo-dyestuffs
IPC: C09B45/16
Filed: 1952-12-15
Abstract: 5 - Pyrazolone - 3 - carboxylic acid amides of formula <FORM:0749826/IV(a)/1> where X1 is H or an alkyl residue containing at most 4 C atoms and X2 is an alkyl, cycloalkyl, aralkyl or aryl residue containing at least 3 C atoms or X1 and X2 together with N form a heterocyclic residue and n is a whole number may be made by converting the free acid to the acid chloride by treatment with, e.g. phosphorus trichloride with subsequent or simultaneous treatment with an appropriate amine. Halogenation may be effected in an inert solvent such as toluene, chlorbenzene or an excess of amine.  The monoalkylamides may also be made by heating an appropriate monoalkylamine with an ester, preferably a lower alkyl ester such as the methyl ester, or with a mixture of esters of a 5 - pyrazolone - 3 - carboxylic acid which is unsubstituted in the 1-position or contains in that position an alkyl residue of at most 6 carbon atoms. Specified amides are 5-pyrazolone-3-carboxylic acid isopropyl-, n-butyl-, 21-ethylhexyl-, cyclohexyl-, benzyl- and (21-, 31- and 41-chloro-)-phenyl-amide, anilide, o-, m- and p-toluidide, N-methyl- and -ethyl-anilide, morpholide and 1-n-butyl-5-pyrazolone-3-carboxylic acid-n-butylamide.  The products are dyestuff intermediates, c.f. Group IV (c).  An example describes the preparation of 5-pyrazolone-3-carboxylic acid-n-butylamide by both methods outlined above.  Specifications 344,250 and 648,364 are referred to.ALSO:The invention comprises complex chromium compounds of monoazo-dyestuffs of formula:- <FORM:0749826/IV(c)/1> where - R - OH is an aromatic residue containing a sulphonic acid group bound to the azo linkage in ortho-position to the hydroxyl group, X1 is H or an alkyl group of up to 4 carbon atoms and X2 is an alkyl, cycloalkyl, aralkyl or aryl residue containing at least 3 carbon atoms, or X1 and X2 together with - N - is a heterocyclic residue and n is an integer, advantageously 1.  Preferred are chromium dyestuffs in which n is 1, X1 is H and X2 is an alkyl residue of at least 3 carbon atoms or an aryl residue. The dyestuffs are made by treating with a chromium yielding agent a dyestuff obtained by coupling, advantageously in an alkaline medium, an ortho-oxy-diazocompound, especially of the benzene or naphthalene series, containing a sulphonic acid group with an appropriate 5 - pyrazolone - 3 - carboxylic acid amine.  The diazo compound may contain further substituents such as methyl, tert. amyl, nitro, acetylamino, methoxy and sulphonic acid groups and especially chlorine atoms. Diazotizable amines specified are 2 - amino - 1 oxybenzene - 4 - or 5 - sulphonic acid, 6 - nitro -, chloro - and - acetylamino - 2 amino - 1 - oxy - benzene - 4 - sulphonic acid, 4 - nitro - and - acetylamino - 2 - amino - 1 - oxy-benzene - 6 - sulphonic acid. 4 - methyl - 2 - amino - 1 - oxybenzene - 5 - sulphonic acid, 5 - nitro - 2 - amino - 1 - oxybenzene - 4 - sulphonic acid, 4-tert. - amyl - and particularly - chloro - 2 - amino - 1 - oxybenzene - 6 - sulphonic acid, 1 - amino - 2 - oxynaphthalene - 4 - sulphonic acid, 6 - bromo -, - nitro - or - methoxy - 1 - amino - 2 - oxynaphthalene - 4 - sulphonic acid and 2 - amino - 1 - oxybenzene - 4, 6 - disulphonic acid.  Amines specified for the formation of amides of the pyrazolone - carboxylic acids are isopropyl -, n - butyl, hexyl -, cyclohexyl -, p - tolyl -, and benzyl - amines aniline, p - chloroaniline, N - methyl and ethyl-aniline and morpholine, and specified pyrazolones are 5 - pyrazolone - 3 - carboxylic acid - isopropyl -, n - butyl, 21 - ethylhexyl -, (21 -, 31 - and 41 - chloro) - phenylcyclohexyl - and benzyl - amide, anilide o, m and p - toluidine, N - methyl - and - ethyl - anilide and morpholide and 1 - n - butyl - 5 - pyrazolone - 3 carboxylic acidn - butylamide.  The chroming is effected so that the resulting dyestuff may be used from a sulphuric acid bath.  Such treatment in substance is advantageously carried out with a salt of trivalent chromium, e.g. the acetate, fluoride or sulphate, advantageously in an acid medium, so that a dyestuff containing about one atom of chromium per dyestuff molecule is obtained. Advantageously chroming is carried out for a long time at about the boiling temperature of the reactionmixture in an open vesse. The dyestuffs are used for dyeing silk, leather and especially wool or synthetic-fibres of superpolyamides or superpolyurethanes.  The dyeings yield blueish-red tints.  An Example and a Table are provided of the use of certain of the above specified components in the preparation of the dyestuffs together with an Example of their use in dyeing wool an azo-component additional to those specified being 5 - pyrazolone - 3 - carboxylic acid sec butylamide.  Specifications 344,250 and 648,364 [Group IV(b)] are referred to.