Table 1 Optimization of the experimental conditions for manual radiofluorination from (S)-3 leading to (S)-[18F]4 intermediate
Entry | precursor (mg) | TBA-HCO3 (µmol) | Anhyd. solvent(s) (v/v)* | Reaction temp. (°C) | Reaction time (min) | RCC** (%) |
|---|---|---|---|---|---|---|
1 | 1 | 7.5 | DMF | 110 | 5 | 58 ± 6 |
2 | 1 | 7.5 | DMF | 110 | 10 | 54 ± 7 |
3 | 1 | 7.5 | DMF | 90 | 5 | 38 ± 3 |
4 | 1 | 7.5 | DMF | 90 | 10 | 39 ± 1 |
5 | 2 | 7.5 | DMF | 110 | 5 | 56 ± 7 |
6 | 4 | 7.5 | DMF | 110 | 5 | 40 ± 6 |
7 | 8 | 7.5 | DMF | 110 | 5 | 18 ± 4 |
8 | 1 | 3.75 | DMF | 110 | 5 | 27 ± 10 |
9 | 1 | 15 | DMF | 110 | 5 | 68 ± 10 |
10 | 1 | 15 | DMF | 130 | 5 | 58 ± 6 |
11 | 1 | 15 | DMF/t-BuOH (9/1) | 110 | 5 | 91 ± 2 |
12 | 1 | 15 | DMF/t-BuOH (8/2) | 110 | 5 | 91 ± 2 |
13 | 1 | 15 | MeCN | 110 | 5 | 97 ± 1 |
14 | 2 | 15 | MeCN | 110 | 5 | 98 ± 1 |
15 | 1 | 15 | MeCN/t-BuOH (8/2) | 110 | 5 | 90 ± 5 |