Table 1. Reaction conditions and optimisation for the synthesis of [¹¹C]1 using DBU as a trapping agent (see footnote ‡).

Entry a	Fluoride source (eq.)	Additive (eq.)	DBU (eq.)	CuI (%)	TE (%)	RCY [11C]1 (%)
1 b	CsF (3)	18-Crown-6 (3)	—	—	6	0
2 b	CsF (3)	18-Crown-6 (3)	—	10	99	0
3 b	CsF (3)	18-Crown-6 (3)	0.6	10	77	0
4 b	KF (3)	K2.2.2 (3)	0.6	10	96	21
5	KF (0.5)	K2.2.2 (0.5)	0.6	10	63 ± 14	41 ± 9
6	KF (0.25)	K2.2.2 (0.25)	0.6	10	52 ± 5	53 ± 23
7 a , c	KF (0.5)	K2.2.2 (0.5)	0.6	10	77	40
8 c	KF (0.25)	K2.2.2 (0.25)	0.6	10	67 ± 13	55 ± 7
9 b , d	KF (0.25)	K2.2.2 (0.25)	0.6	10	37	0
10	KF (0.25)	K2.2.2 (0.25)	0.9	10	86 ± 5	28 ± 11
11	KF (0.25)	K2.2.2 (0.25)	0.6	20	61 ± 31	44 ± 26
12 b , c , e	KF (0.25)	K2.2.2 (0.25)	0.6	10	7	15

^a n = 3.

^b n = 1.

^c140 °C.

^d70 °C.

^eTHF.