반응 #40775

반응 방정식

hydrazine hydrate

diethylether

2-Methyl-3-phenyl-propenal

→

desired product

4-Methyl-5-phenyl-4,5-dihydro-1H-pyrazole

용매

H2O

반응 조건

후처리

1. 1
   온도The emulsion was cooled with an ice bath
2. 2
   기타the organic layer was separated
3. 3
   추출the aqueous layer was extracted with diethylether
4. 4
   건조The combined organic layers were dried over Na2SO4
5. 5
   여과filtrated
6. 6
   농축concentrated in vacuo
7. 7
   workup.DISTILLATIONVacuum distillation

실험 절차

5.22 ml (1 equiv.) hydrazine hydrate was added to 100 mL diethylether. The emulsion was cooled with an ice bath. 15.0 mL 2-Methyl-3-phenyl-propenal was added dropwise, and the mixture was stirred overnight at room temperature. H2O was added, the organic layer was separated and the aqueous layer was extracted with diethylether. The combined organic layers were dried over Na2SO4, filtrated and concentrated in vacuo. Vacuum distillation yielded 5.9 g of desired product (mixture of diastereomeric pairs) as a clear fluid (76-82° C., 0.2-0.3 mbar). 1H NMR (400 MHz, CDCl3) of first diastereomeric pair; δ 0.71 (d, J=7 Hz), 3H), 3.20-3.31 (m, 1H), 4.77 (d, J=10 Hz, 1H), 6.73 (br s, 1H), 7.23-7.42 (m, 5H), 8.55-8.60 (m, 2H). 1H NMR (400 MHz, CDCl3) of second diastereomeric pair: δ 1.24 (d, J=7 Hz), 3H), 2.90-3.11 (m, 1H), 4.22 (d, J=11 Hz, 1H), 6.71 (br s, 1H), 7.23-7.42 (m, 5H), 8.55-8.60 (m, 2H).

출처