Patent ID: 8865895

Claim:
A 6,7-dihydrobenzimidazo[1,2-c]quinazolin-6-one derivative of the general structural formula I wherein X is a carboxylic group COOH, m is 0, 1, 2 or 3; Y is a sulfonic group SO 3 H, n is 0, 1, 2 or 3; Z is an amide group L-NH 2 , wherein L is a linking group, p is 0, 1, 2 or 3; K is a counterion selected from the group consisting of H + , NH 4 + , Na + , K + , Li + , Mg 2+ , Ca 2+ , Zn 2+ and Al 3+ , s is the number of counterions providing neutral state of the molecule; R is a substituent selected from the group consisting of CH 3 , C 2 H 5 , NO 2 , Cl, Br, F, CF 3 , CN, OH, OCH 3 , OC 2 H 5 , OCOCH 3 , OCN, SCN, NH 2 , and NHCOCH 3 , w is 0, 1, 2, 3 or 4; R 1 is a substituent selected from the group consisting of H, CH 3 , C 2 H 5 , C 3 H 7 , i-C 3 H 7 , CH 2 CH 2 CH 2 CH 3 , CH(CH 3 )CH 2 CH 3 , CH 2 CH(CH 3 )CH 3 and C(CH 3 ) 3 ; and wherein the values of at least two of said integers m, n and p are not equal to 0 and said derivative comprises at least two different groups selected from the list comprising X, Y, and Z; and wherein said derivative does not substantially absorb incident electromagnetic radiation in the visible spectral range.