تفاعل #58925

معادلة التفاعل

2-(4-nitrophenyl)acetohydrazide

ethyl chlorocarbonate

diphosphorus pentaoxide

hexamethyldisiloxane

→

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

المردود 51.2%

المذيبات

Water

N,N-dimethylacetamide

1,2-dichlorobenzene

Water

ظروف التفاعل

المعالجة

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

الإجراء التجريبي

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.

المصدر