反应详情

To the ethyl acetate solution of 5-deoxy-L-arabinose phenylhydrazone obtained in the step (3) of the preceding example, 9.0 g (0.074 mol) of 4-dimethylaminopyridine (DMAP) was added and dissolved therein. Then 120.82 g (1.183 mol) of acetic anhydride was added by dripping to the solution at an ambient temperature of 10° C. After stirring overnight at the same ambient temperature, 250 me of water was added to the solution, which was then stirred for 30 minutes. After allowing the solution to stand, it was separated into a water layer and an organic layer, and a 20% aqueous solution of sodium hydroxide was added to the organic layer up to its neutralization. Then after allowing the solution to stand, its organic layer was separated out and dried over anhydrous sodium sulfate. When the thus treated ethyl acetate solution was subjected to vacuum concentration, an ethyl acetate solution of triacetoxy-5-deoxy-L-arabinose phenylhydrazone was obtained.

1. additionwas added
2. dissolutiondissolved
3. customby dripping to the solution at an ambient temperature of 10° C
4. additionwas added to the solution, which
5. customit was separated into a water layer
6. additionan organic layer, and a 20% aqueous solution of sodium hydroxide was added to the organic layer up to its neutralization
7. customits organic layer was separated out
8. dry with materialdried over anhydrous sodium sulfate
9. concentrationWhen the thus treated ethyl acetate solution was subjected to vacuum concentration