Реакция #40773

Уравнение реакции

hydrazine hydrate

cinnamaldehyde

→

5-Phenyl-4,5-dihydro-1H-pyrazole

Растворители

t-BuOH

Условия реакции

Обработка

1. 1
   ТемператураThe mixture was refluxed overnight
2. 2
   Концентрированиеfollowed by concentration under reduced pressure
3. 3
   workup.ADDITIONWater was added to the residue
4. 4
   Экстракцияthe aqueous phase was extracted twice with DCM
5. 5
   ПромывкаThe combined organic layers were washed with water
6. 6
   Сушкаdried over Na2SO4
7. 7
   Концентрированиеconcentrated under reduced pressure
8. 8
   workup.ADDITIONThis gave 10.46 g of a yellow oil containing 85% of the desired product, which
9. 9
   Другоеwas used in subsequent steps without further purification

Методика

Under N2 atmosphere, hydrazine hydrate (9.2 mL) was added to a solution of cinnamaldehyde (10.0 g) in t-BuOH (20 mL). The mixture was refluxed overnight, followed by concentration under reduced pressure. Water was added to the residue, and the aqueous phase was extracted twice with DCM. The combined organic layers were washed with water, dried over Na2SO4 and concentrated under reduced pressure. This gave 10.46 g of a yellow oil containing 85% of the desired product, which was used in subsequent steps without further purification. 1H NMR (200 MHz, CDCl3) δ 2.61-2.80 (m, 1H), 3.04-3.23 (m, 1H), 4.72 (dd, J=8 and 10 Hz, 1H), 5.60-6.10 (br s, 1H), 6.77-6.87 (m, 1H), 7.18-7.47 (m, 5H).

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