Ciba-geigy Ag

Ilford Limited

Victor W Dolden

Geoffrey E Ficken

Rolf Steiger

Rainer Kitzing

Clive W Mowforth

Trevor J Maternaghan

Douglas J Edwards

Compounds of the formula ##STR1## where A represents the atoms necessary to complete a benzoxazole or naphthoxazole ring which is optionally substituted, R.sub.1 and R.sub.2 are each alkyl, hydroxyalkyl or alkoxy alkyl groups wherein the alkyl moiety comprises 1 to 4 carbon atoms, R.sub.3, R.sub.4, R.sub.5 and R.sub.6 are each hydrogen atoms or alkyl groups having 1 to 4 carbon atoms or phenyl groups, and X is an anion.

Monomethine compounds

Sulphoalkyl quaternary salts of the formula ##STR1## wherein X is --O--, --Se--, --S--, --NR-- or --CR(R)--, R is hydrogen or alkyl, R.sub.1 is hydrogen, methyl or ethyl, R.sub.2 and R.sub.3 are each hydrogen or substituents or together represent the atoms necessary to complete an optionally substituted benzene ring, R.sub.4 is optionally substituted alkylene of 3 or 4 carbon atoms and n is 1 or 0, except that when n is 1, R.sub.1 cannot be hydrogen, are prepared by heating at a temperature above 80.degree. C. a heterocyclic base of the formula ##STR2## wherein X, R.sub.1, R.sub.2, R.sub.3 and n have the indicated meanings with a hydroxysulphonic acid of the formula HOR.sub.4 SO.sub.3 H.

Preparation of sulphoalkyl quaternary salts

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Wilmslow, United Kingdom

Victor W Dolden