반응 #58925

반응 방정식

2-(4-nitrophenyl)acetohydrazide

ethyl chlorocarbonate

diphosphorus pentaoxide

hexamethyldisiloxane

→

5-(4-nitrobenzyl)-1,3,4-oxadiazol-2(3H)-one

수율 51.2%

용매

Water

N,N-dimethylacetamide

1,2-dichlorobenzene

Water

반응 조건

후처리

1. 1
   추출the mixture was extracted with ethyl acetate
2. 2
   세척The organic layer was washed successively with saturated aqueous sodium hydrogen carbonate and saturated brine
3. 3
   건조dried over anhydrous magnesium sulfate
4. 4
   농축concentrated
5. 5
   기타to give colorless crystals
6. 6
   workup.STIRRINGwas stirred at 160° C. for 2 hrs
7. 7
   추출the mixture was extracted with ethyl acetate
8. 8
   세척The organic layer was washed successively with saturated aqueous sodium hydrogen carbonate and saturated brine
9. 9
   건조dried over anhydrous magnesium sulfate
10. 10
    농축concentrated

실험 절차

A mixture of 2-(4-nitrophenyl)acetohydrazide (0.50 g), ethyl chlorocarbonate (0.34 g) and N,N-dimethylacetamide (10 mL) was stirred at room temperature for 1 hr. Water was added to the reaction mixture, and the mixture was extracted with ethyl acetate. The organic layer was washed successively with saturated aqueous sodium hydrogen carbonate and saturated brine, dried over anhydrous magnesium sulfate, and concentrated to give colorless crystals. A mixture of the obtained crystals, diphosphorus pentaoxide (1.50 g), hexamethyldisiloxane (2.96 g) and 1,2-dichlorobenzene (10 mL) was stirred at 160° C. for 2 hrs. Water was added to the reaction mixture, and the mixture was extracted with ethyl acetate. The organic layer was washed successively with saturated aqueous sodium hydrogen carbonate and saturated brine, dried over anhydrous magnesium sulfate, and concentrated to give 5-(4-nitrobenzyl)-1,3,4-oxadiazol-2(3H)-one as pale-yellow crystals (0.29 g, yield 50%). Recrystallization thereof from ethyl acetate-hexane gave pale-yellow prism crystals. melting point: 170-171° C.

출처