Table 2.
Optimization of reaction conditions for the synthesis of [18F]12.
 | |||||
|---|---|---|---|---|---|
| Entry | Solventa | T (°C) | Subst. (mg) | Base (mg) | RCC (%)b |
| 1 | CH3CN | 120 | 2 | K2CO3/K222 (2/10) | 1 ± 0 (n = 2) |
| 2 | DMF | 120 | 2 | K2CO3/K222 (2/10) | 12 ± 2 (n = 2) |
| 3 | DMF | 120 | 2 | TEAB (2) | 7 ± 3 (n = 2) |
| 4 | DMF | 120 | 2 | KHCO3/K222 (2/10) | 3 ± 3 (n = 2) |
| 5 | DMF | 120 | 2 | TBAOMs (2) | 11 ± 1 (n = 2) |
| 6 | tBuOH/MeCN | 100 | 2 | TBAOMs (3) | 80 ± 16 (n = 2) |
| 7 | tBuOH/MeCN | 100 | 3 | TBAOMs (3) | 91 ± 1 (n = 2) |
| 8 | tBuOH/MeCN | 80 | 3 | TBAOMs (3) | 59 ± 8 (n = 2) |
| 9 | tBuOH/MeCN | 120 | 3 | TBAOMs (3) | 77 ± 1 (n = 2) |
a
0.4 mL, tBuOH/MeCN = 0.35/0.05 for entries 6–9.
b
Incorporation yield and product identity were determined by radio-TLC and radio-HPLC, respectively. The optimal conditions (entry 7) are indicated in bold.