反应详情

温度

60 °C

The product from Example 7C (0.34 g) was treated with 4-nitrophenyl 1,3-thiazol-5-ylmethyl carbonate [prepared from 4-nitrophenyl 1,3-thiazol-5-ylmethyl carbonate hydrochloride salt (0.63 g, 1.99 mmol) by extraction with aqueous NaHCO3] in ethyl acetate (10 mL). The mixture was stirred at 60° C. under a N2 atmosphere overnight. The mixture was diluted with ethyl acetate (50 mL), extracted with 10% aqueous K2CO3 (3×20 mL), washed with water (20 mL) and brine, dried over Na2SO4, filtered, and concentrated under reduced pressure. The residue was subjected to column chromatography on silica gel (ethyl acetate:hexanes, 2:1) to provide the two title compounds combined and a third separated product. The mixture of (S,S) and (R,R) enantiomers were obtained as a colorless amorphous solid. Rf=0.32 (ethyl acetate); 1H NMR (CDCl3) δ 8.73 (s, 2H), 7.75 (s, 2H), 7.30-7.11 (m, 10H), 5.53 (br s, 2H), 5.23 (d, J=12.9 Hz, 2H), 5.16 (d, J=13.2 Hz, 2H), 3.91 (m, 2H), 2.90-2.79 (m, 2H), 2.68 (dd, J=7.5, 13.6 Hz, 2H), 2.42 (t, J=12 Hz, 2H), 2.26 (dd, J=1, 12 Hz, 2H), 1.99 (d, J=13.9 Hz, 1H), 1.87 (d, J=14.2 Hz, 1H), 0.71 (s, 9H); MS (ESI+) m/z 636 (M+H)+.

1. extractionextracted with 10% aqueous K2CO3 (3×20 mL)
2. washwashed with water (20 mL) and brine
3. dry with materialdried over Na2SO4
4. filtrationfiltered
5. concentrationconcentrated under reduced pressure
6. customto provide the two title compounds
7. additionThe mixture of (S,S)
8. custom(R,R) enantiomers were obtained as a colorless amorphous solid