反应详情

A mixture of 0.39 g (0.91 mmol) of Dess-Martin periodinane and 0.07 g (0.91 mmol) of tert-butyl alcohol in dichloromethane (2 ml) was allowed to stir at room temperature for 20 minutes. The solution was cooled to 0° C. and to this was added 0.15 g (0.45 mmol) of the above-prepared 2-hydroxy-3-methyl-4-oxo-4-(2-phenyl-thiazol-5-yl)-butyric acid ethyl ester in dichloromethane (2 ml). The reaction was stirred at 0° C. for 3 hours and quenched with sodium bisulfite in 50% aqueous sodium bicarbonate. The mixture was diluted with dichloromethane and allowed to stir for 20 minutes at room temperature. The organic phase was washed twice with aqueous sodium bicarbonate, once with water, once with brine, and dried over sodium sulfate. The solvent was evaporated under reduced pressure and dissolved in ethyl alcohol (5 ml). 41 mg (0.68 mmol) of glacial acetic acid was added followed by the addition of 34 mg (0.68 mmol) of hydrazine monohydrate. The solution was allowed to stir at room temperature for 4 hours. The solvent was evaporated under reduced pressure and the residue was purified by chromatography on silica gel using 1:99 ethyl alcohol:dichloromethane as eluant to give 0.035 g of the title compound (25%). 1H NMR (500 MHz, CDCl3) δ 8.08 (s, 1H) 8.00 (d, 2H) 7.47 (m, 3H) 4.45 (q, 2H) 2.54 (s, 3H) 1.44 (t, 3H).

1. temperatureThe solution was cooled to 0° C.
2. stirringThe reaction was stirred at 0° C. for 3 hours
3. customquenched with sodium bisulfite in 50% aqueous sodium bicarbonate
4. additionThe mixture was diluted with dichloromethane
5. stirringto stir for 20 minutes at room temperature
6. washThe organic phase was washed twice with aqueous sodium bicarbonate, once with water, once with brine
7. dry with materialdried over sodium sulfate
8. customThe solvent was evaporated under reduced pressure
9. dissolutiondissolved in ethyl alcohol (5 ml)
10. stirringto stir at room temperature for 4 hours
11. customThe solvent was evaporated under reduced pressure
12. customthe residue was purified by chromatography on silica gel using 1:99 ethyl alcohol