Table 1.

Structures and affinities of compound 1 and analogues 25–35^a,^b

	R2
R1
	1	28	32
	9.6 ± 0.22	11 ± 1.7	NA
	25	29	33
	12 ± 2.5	15 ± 4.2	NA
	26	30	34
	NA	NA	NA
	27	31	35
	12 ± 2.3	14 ± 2.9	NA

^aK_i values are shown as mean ± SEM in µM based on at least three individual measurements.

^bNA: no affinity.