Table 1.
Conditions for direct radiomethylation of 3 with MeI. Reaction time for all reactions was set to 5 min. Radiochemical conversions (%) were calculated from semipreparative HPLC chromatograms.
|
Solvent |
Base |
Temperature [°C] |
2 [%] |
4 [%] |
5 [%] |
|---|---|---|---|---|---|
|
DMSO |
NaOH, 5 μL 5 m |
110 |
0 |
28.2 |
58.5 |
|
DMSO |
Cs2CO3 |
110 |
0 |
18.4 |
45.4 |
|
DMSO |
NaHCO3 |
110 |
2.1 |
7.2 |
14.6 |
|
DMSO |
– |
110 |
9.3 |
0 |
0 |
|
DMF |
– |
110 |
0 |
0 |
0 |