Table 3. mGlu₅ Potency and Rat Brain Penetration SAR in Sulfide Bridged Analogues.

entry	series	A	R1	mGlu5 IC50 (nM)	rat B/P ratio
34	I	CH	H	19	<0.01
35	I	CH	Me	87	0.10
36	I	N	H	18	<0.01
37	II	CH	H	24	0.09
38	II	CH	Me	30	0.16
39	II	N	H	41	0.04
40	III	CH	H	146	<0.01
41	III	CH	Me	380	0.02
42	III	N	H	19	0.26