반응 #1395

반응 방정식

sodium hydroxide

(R)-tert-leucinol

water

chloroformic acid ethyl ester

→

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

수율 80.0%

용매

toluene

반응 조건

후처리

1. 1
   온도The mixture was then heated to 60°-65° C. at pH 8.0
2. 2
   기타the aqueous phase separated
3. 3
   온도slowly heated
4. 4
   workup.ADDITIONafter the addition of 0.4 g finely granulated sodium hydroxide at 70° C
5. 5
   기타produced during the reaction
6. 6
   기타was separated from 70°-100° C
7. 7
   workup.ADDITIONwas added
8. 8
   기타the aqueous phase separated
9. 9
   온도warm water which
10. 10
    기타was 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
    농축was concentrated to 120 ml
13. 13
    여과filtered hot
14. 14
    온도slowly cooled off under agitation, during which the product
15. 15
    기타separated in colorless crystals
16. 16
    여과These crystals were filtered off after 30 min agitation at 5° C.
17. 17
    세척washed with cold toluene
18. 18
    기타dried in a vacuum at 50° C

실험 절차

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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