Patent ID: 8921124

Claim:
A compound represented by the following general formula [50], and a salt thereof: [wherein R 1′ to R 6′ each independently represent an alkyl group which may substitute a group represented by the general formula [2]: —COOR 12 [2] (wherein R 12 represents hydrogen atom, C 1 to C 10 alkyl group, alkali metal atom, organic ammonium ion, ammonium ion or anion) or a group represented by the general formula [3]: —SO 3 R 13 [3] (wherein R 13 represents hydrogen atom, alkali metal atom, organic ammonium ion, ammonium ion or anion); R 7′ to R 10′ each independently represent a hydrogen atom, the group represented by the general formula [2] or the group represented by the general formula [3]; R 11′ represents hydrogen atom or alkyl group, being able to have substituents; and n represents an integer of from 0 to 3, provided that any of R 1′ and R 2′ , R 4′ and R 5′ , R 1′ and R 6′ , and R 2′ and R 4′ may form a bivalent group with a group selected from groups represented by the general formulae [52] to [54]: (wherein R 50 represents hydrogen atom or alkyl group being able to have substituents), and substituted or unsubstituted alkylene group; and in the case where said bivalent group is formed, at least one of R 1′ to R 11′ , along with the bivalent group formed by any of R 1′ and R 2′ , R 4′ and R 5′ , R 1′ and R 6′ , and R 2′ and R 4′ , has the group represented by the general formula or the group represented by the general formula [3]; and in the case where said bivalent group is not formed, at least one of R 1′ to R 11′ has the group represented by the general formula or the group represented by the general formula [3]].