. 2016 Feb 8;6:20422. doi: 10.1038/srep20422

Table 1. Radiosynthesis of [¹⁸F]CB251 under various conditions^a.

entry	base	solvent	time (min)	temp. (°C)	RCY (%)^b
1	nBu₄NHCO₃ (0.8 equiv.)	CH₃CN	10	120	<1
2	nBu₄NHCO₃ (0.8 equiv.)	DMSO	10	140	<1
3	nBu₄NHCO₃ (0.8 equiv.)	DMF	10	140	<1
4	nBu₄NHCO₃ (0.8 equiv.)	tert-BuOH	10	120	4.1 ± 1.5^b
5	nBu₄NHCO₃ (0.8 equiv.)	tert-BuOH	30	120	4.0 ± 1.2^b
6	nBu₄NHCO₃ (2.0 equiv.)	tert-BuOH	10	120	17.3 ± 4.9^b
7	nBu₄NHCO₃ (4.0 equiv.)	tert-BuOH	10	120	28.1 ± 7.2^c
8	nBu₄NHCO₃ (8.0 equiv.)	tert-BuOH	10	120	10.6 ± 4.8^b
9	K_2.2.2/K₂CO₃ (5 mg/0.8 equiv.)	tert-BuOH	10	120	14.7 ± 4.2^b
10	K_2.2.2/K₂CO₃ (5 mg/2.0 equiv.)	tert-BuOH	10	120	1.7 ± 0.5^b

^aThe reaction was carried out using different equivalents of base relative to the precursor (3.0 mg) in 0.4 mL of solvent.

^bThe radiochemical yield (RCY) was determined by radio-TLC (n = 3).

^cn = 21.

Table 1. Radiosynthesis of [18F]CB251 under various conditionsa.