反应详情

To 2-hydroxy-4-methylpentanoic acid methyl ester was added 150 ml of 12.5% phosgene in toluene and 25 drops of dimethylformamide. After stirring for 16 h at room temperature, the solvent was evaporated and the residue chased several times with benzene. The resulting product was dissolved in methylene chloride (50 ml), cooled to 0° C. and treated by dropwise addition with 3.86 g (0.044 mol) of morpholine. The reaction mixture was stirred for 2 h at 0°-5° C. and then distributed between 0.5N HCl and methylene chloride. The organic phase was washed with aqueous NaHCO3 and brine and evaporated to a residue. Flash chromatography on silica gel gave the desired compound.

1. customthe solvent was evaporated
2. dissolutionThe resulting product was dissolved in methylene chloride (50 ml)
3. temperaturecooled to 0° C.
4. stirringThe reaction mixture was stirred for 2 h at 0°-5° C.
5. washThe organic phase was washed with aqueous NaHCO3 and brine
6. customevaporated to a residue