| abstract |
Compounds having the general formula: ##STR1## where A is a C 1 -C 4 straight or branched chain alkylene radical, B is a --SO 3 M, --CO 2 M, --PO 3 HM or --PO 3 M 2 grouping, n M is hydrogen, or a cation giving a water-soluble derivative, n R is hydrogen, a cation giving a water-soluble derivative or a C 1 -C 4 straight or branched alkyl, R 1 is hydrogen, methyl or --COOH, and m is 0 or 1 and processes of preparing them. |