反応 #1395

反応方程式

sodium hydroxide

(R)-tert-leucinol

water

chloroformic acid ethyl ester

→

(R)-4-tert-butyl-2-oxazolidinone

収率 80.0%

溶媒

toluene

反応条件

後処理

1. 1
   温度The mixture was then heated to 60°-65° C. at pH 8.0
2. 2
   その他the aqueous phase separated
3. 3
   温度slowly heated
4. 4
   workup.ADDITIONafter the addition of 0.4 g finely granulated sodium hydroxide at 70° C
5. 5
   その他produced during the reaction
6. 6
   その他was separated from 70°-100° C
7. 7
   workup.ADDITIONwas added
8. 8
   その他the aqueous phase separated
9. 9
   温度warm water which
10. 10
    その他was separated again after a brief agitation at 65° C
11. 11
    workup.DISTILLATIONAfter distilling the organic phase on a water separator the phase
12. 12
    濃縮was concentrated to 120 ml
13. 13
    ろ過filtered hot
14. 14
    温度slowly cooled off under agitation, during which the product
15. 15
    その他separated in colorless crystals
16. 16
    ろ過These crystals were filtered off after 30 min agitation at 5° C.
17. 17
    洗浄washed with cold toluene
18. 18
    その他dried in a vacuum at 50° C

実験手順

73 g (containing 0.25 mole (R)-tert-leucinol) of the filtrate cited in example 6 was taken up with 27 ml water and 200 ml toluene. 25 ml (0.26 mole) chloroformic acid ethyl ester were then added dropwise at 20°-25° C., during which the pH was maintained at 7-8.5 by the addition of 10 M sodium hydroxide solution. The mixture was then heated to 60°-65° C. at pH 8.0 and the aqueous phase separated. The toluene phase was dehydrated on a water separator under a slight vacuum and slowly heated after the addition of 0.4 g finely granulated sodium hydroxide at 70° C. A total of 40 ml distillate which contained the ethanol produced during the reaction was separated from 70°-100° C . After cooling of the batch to 65° C. a solution of 0.6 ml glacial acetic acid in 10 ml water was added, the mixture briefly agitated, the aqueous phase separated and the toluene phase compounded again with 15 ml warm water which was separated again after a brief agitation at 65° C. After distilling the organic phase on a water separator the phase was concentrated to 120 ml, filtered hot and slowly cooled off under agitation, during which the product separated in colorless crystals. These crystals were filtered off after 30 min agitation at 5° C., washed with cold toluene and dried in a vacuum at 50° C. 28.6 g (R)-4-tert-butyl-2-oxazolidinone (80% yield) was obtained. A 1H-NMR spectrum corroborated the structure of the product.

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