Patent ID: 7569337

Claim:
A compound of the formula in which R 1 and R 2 are both hydrogen; R 3 and R 4 , together with the nitrogen atom to which they are attached, form a group of the formula in which R 5 is hydrogen, (CH 2 ) n I, (CH 2 ) n 123 I, (CH 2 ) n OH, CH 3 , 11 CH 3 , (CH 2 ) n F or (CH 2 ) n 18 F, n being 2, 3, or 4; and R is a group of the formula in which X is S, Y is N, and R 6 and R 7 , independently, are hydrogen, NO 2 , F, 18 F, O(CH 2 ) n F, O(CH 2 ) n 18 F, Cl, CN, 11 CN, OCH 3 , O 11 CH 3 , I, 123 I, O(CH 2 ) n I or O(CH 2 ) n 123 I, n being 2, 3, or 4; in free base form or in acid addition salt form.