| 主权项 |
1. A compound having the formula: or an ester or a salt thereof, wherein A is selected from the group consisting of:
(a) substituted and unsubstituted C6-C10 aryl; and(b) substituted and unsubstituted C3-C7 heteroaryl; R1 is selected from the group consisting of:
(a) methoxy; and(b) ethoxy; R2 is selected from the group consisting of hydrogen, C1-C3 alkyl, C1-C3 alkyl substituted with one or more halogens, and substituted piperazine; X is O or S; Ra, Rb, Rc, and Rd are independently selected from the group consisting of hydrogen, halogen, nitro, C1-C3 alkyl, and C1-C3 alkyl substituted with one or more halogens; Z is a reporting group that provides an optical signal when released from the compound; and n is 0 or 1. |
