SYNTHESIS OF RACEMIC (S)-(+)-[METHYL-C-11]AMPHETAMINE OR (R)-(-)-[METHYL-C-11]AMPHETAMINE
Gee, A; Langstrom, B
| HERO ID | 4935886 |
|---|---|
| In Press | No |
| Year | 1991 |
| Title | SYNTHESIS OF RACEMIC (S)-(+)-[METHYL-C-11]AMPHETAMINE OR (R)-(-)-[METHYL-C-11]AMPHETAMINE |
| Authors | Gee, A; Langstrom, B |
| Journal | Acta Chemica Scandinavica |
| Volume | 45 |
| Issue | 4 |
| Page Numbers | 431-435 |
| Abstract | The synthesis of racemic (S)-(+)- or (R)-(-)-[methyl-C-11]amphetamine (3) is reported. The alkylation of dimethyl 2-benzylmalonate with [C-11]methyl iodide yielded dimethyl 2-benzyl-2-([C-11]methyl)malonate (1) which was used as an intermediate in the synthesis of 3. Hydrolysis of 1 with NaOH and subsequent decarboxylation using glacial acetic acid and heating produced 2-benzyl-[3-C-11]propionic acid (2). Conversion of 2 into 3 was achieved via the intermediate isocyanate using diphenyl-phosphoryl azide (DPPA), and subsequently into the amine using conc. HCl. After purification by solid-phase extraction and preparative LC, (+/-)-3 was obtained with a radiochemical purity greater than 98 %. Starting with 3 GBq (81 mCi) [C-11]carbon dioxide, 145 MBq (3.9 mCi) (+/-)-[methyl-C-11]amphetamine was obtained in 45 min with a 22 % decay-corrected radiochemical yield. Enantiomerically pure 3 was obtained by the preparative LC separation of the (+)- or (-)-10-camphorsulfonamide derivatives of the racemate with a total decay-corrected radiochemical yield of 7 % (counted from the start of methyl iodide synthesis). In a typical synthesis, 27 MBq (0.7 mCi) enantiomerically pure (S)-(+)- or (R)-(-)-[methyl-C-11]amphetamine were obtained starting from 3 GBq (81 mCi) [C-11]carbon dioxide. The position of labelling was confirmed by a C-13 synthesis using the same reaction pathway, and analysis by C-13 NMR spectroscopy. |
| Doi | 10.3891/acta.chem.scand.45-0431 |
| Wosid | WOS:A1991FL08300017 |
| Is Certified Translation | No |
| Dupe Override | No |
| Is Public | Yes |