Table 2.

Structures and Binding Affinity for Analogues 40, 42–59, and 61–69 at the hM₁ and hM₅ mAcChRs^a

compd	R1	R2	R3	Ki, nM
				hM1	hM5	hM1/hM5
40		4-MeO-Bn	Ph	>100,000	>100,000	-
42	ibid.	Me	Ph	20	30	0.7
43	ibid.	nPr	Ph	>100,000	>100,000	-
44	ibid.	nBu	Ph	>100,000	>100,000	-
45		Me	Ph	290	60	4.8
46	ibid.	nPr	Ph	>100,000	>100,000	-
47	ibid.	nBu	Ph	>100,000	>100,000	-
48		Me	Ph	5,400	1,160	4.7
49		Me	Ph	>100,000	>100,000	-
50		Me	Ph	920	630	1.5
51		Me	Ph	340	190	1.8
52		Me	Ph	510	110	4.6
53		Me	Ph	880	280	3.1
54		Me	Ph	330	80	4.1
55		Me	Ph	2,700	740	3.6
56		Me	Ph	25,300	2,240	11.3
57		Me	Ph	24,400	5,040	4.8
58		Me	Ph	>100,000	>100,000	-
59		Me	Ph	6,190	3,070	2.0
61		Et	4-F-Ph	7,900	2,350	3.4
62	ibid.	Me	3-F-Ph	>100,000	>100,000	-
63	ibid.	Me	2-F-Ph	5,270	740	7.0
64	ibid.	Me	3-MeO-Ph	2,430	2,680	0.9
65	ibid.	Me	2-MeO-Ph	8,350	2,410	3.5
66		Me	3-F-Ph	27,000	3,340	8.1
67	ibid.	Me	2-F-Ph	>100,000	>100,000	-
68	ibid.	Me	3-MeO-Ph	>100,000	>100,000	-
69	ibid.	Me	2-MeO-Ph	>100,000	>100,000	-

^aAt least three independent experiments with samples evaluated in duplicate were performed to obtain the K_i value.