Table 2.

Different reducing agents explored for the nitrile reduction of compound [¹⁸F]1 into [¹⁸F]2.

Entry 1	Reducing Agents	Reaction Conditions	[18F]2 Conversion 2	Side Products Conversion 2
1	LAH (100 µmol)	THF, r.t., 5min	15%	85%
2	LAH (100 µmol)	THF, 50 °C, 5min	50%	50%
3	BH3.THF (200 µmol)	THF, r.t., 15 min	5%	91%
4	BH3.THF (200 µmol)	THF, 65 °C, 5 min	5%	91%
5	H2 (1 atm)	Pd/C (150 µg), MeOH, r.t., 5 min	0%	30%
6	[RuCl2(p-cymene)2] (1.5 µmol)	DPPP, NaOH 3M iPrOH, 100 °C, 15 min	10%	-
7	NaBH4 (400 µmol), NiCl2 6H2O (4 µmol)	MeOH, r.t., 5 min	42%	22%
8	BER (500 mg), NiCl2 6H2O (20 mg)	MeOH	<5%	-

¹ Experiments were performed at least in duplicate. ² Conversion rates of [¹⁸F]2 and side products were measured by radio-HPLC as the ratio of formed [¹⁸F]2 or side products, respectively, over the total radioactivity. Best conditions were highlighted in red.