反应详情

5-Benzyl-7-t-butoxycarbonylamino-4-oxo-7-methyl-5-azaspiro[2.4]heptane (43.63 g) was dissolved in toluene, and the solution was stirred under ice-cooling. 37% Concentrated hydrochloric acid (100 mL) was added dropwise thereto, followed by stirring. After 0.5 hours, water was added to the reaction mixture. The mixture was stirred and left to stand so as to separate the aqueous layer from the organic layer. Sodium hydroxide (54 g) was added to and dissolved in the separated aqueous layer so as to alkalify the layer. The aqueous layer was extracted several times with toluene repeatedly. All the toluene layers were combined and washed with saturated brine. The washed toluene layer was dried with sodium sulfate, followed by filtration. The filtrate was concentrated under reduced pressure, to thereby yield the title product (21.29 g, yield: 90.2%).

1. temperaturecooling
2. stirringby stirring
3. stirringThe mixture was stirred
4. waitleft
5. customto separate the aqueous layer from the organic layer
6. additionSodium hydroxide (54 g) was added to and
7. dissolutiondissolved in the separated aqueous layer so as
8. extractionThe aqueous layer was extracted several times with toluene repeatedly
9. washwashed with saturated brine
10. dry with materialThe washed toluene layer was dried with sodium sulfate
11. filtrationfollowed by filtration
12. concentrationThe filtrate was concentrated under reduced pressure