Table 1.

Optimization of the [¹¹C]UCB-J synthesis

Method	Reaction steps	[11C] CH3I[GBq]c	Precursor [mg]	Solvent	Reaction temperature	Reaction Time (min)	[11C]UCB-J [MBq]d	RCYe	nf
I	2a	18 ± 4	1.2 ± 0.1	DMF-H2O (8:1)	30 °C + 100 °C	3 + 5	53 ± 15	< 1%	3
I	2a	18; 20	3.0; 3.0	DMF-H2O (8:1)	30 °C + 100 °C	3 + 5	138; 216	3%; 4%	2
II	2a	21 ± 4	1.1 ± 0.1	THF-H2O (34:4)	30 °C + 70 °C	3 + 5	890 ± 240	16 ± 5%	7
III	1b	17 ± 2	1.1 ± 0.1	THF-H2O (35:4)	70 °C	4	1780 ± 460	39 ± 5%	9

^aFormulated by vortex evaporator method

^bFormulated by Sep-Pak method

^cStarting activity

^dAt EOS

^eRCY based on [¹¹C]CH₃I

^fNumber of experiments