反应详情

Methyl-5-(piperidin-3-yl)-1,2,4-oxadiazole (0.83 g, 0.0050 mol) and D-tartaric acid (0.74 g, 0.0050 mol) were dissolved in hot methanol (10 mL) and the solution was refluxed for 15 minutes. 30 mL of acetonitrile was added and the resulting solution was allowed to cool to room temperature. The crystals were filtered, washed with 10 mL of 1:3 methanol:acetonitrile, and recrystallized 3 times from methanol:acetonitrile (10 mL 20 mL) as before to give the D-tartrate salt of S-(+)-3-methyl-5-piperidin-3-yl)-1,2,4-oxadiazole (3a), 193 mg white solid. The optical purity 100% ee, as determined by HPLC analysis (Chiral Technologies Chiral-AGP, 4.0 mm×150 mm, 0.5% methanol 20 mM sodium phosphate pH=7). MS (ESI) m/z 168 [M+1]+. 1H NMR (DMSO-d6) δ 1.67-1.79 (m, 3H), 2.10-2.13 (m, 1H), 2.33 (s, 3H), 2.76-2.82 (t, 1H), 3.01-3.14 (m, 2H), 3.31-3.36 (m, 1H), 3.44-3.47 (m, 1H), 3.95 (s, 1H).

1. temperaturethe solution was refluxed for 15 minutes
2. filtrationThe crystals were filtered
3. washwashed with 10 mL of 1:3 methanol
4. customacetonitrile, and recrystallized 3 times from methanol