Реакция #1607402

Уравнение реакции

LDA

ethyl 1-(4-methoxybenzyl)-1H-pyrazole-4-carboxylate

Butyl lithium

diisopropylamine

N-methoxy-N-methylcyclopropanecarboxamide

→

ethyl 3-(cyclopropanecarbonyl)-1-(4-methoxybenzyl)-1H-pyrazole-4-carboxylate

Выход 9.7%

Растворители

THF

THF

AcOEt

THF

Условия реакции

Обработка

1. 1
   Другоеat room temperature
2. 2
   workup.STIRRINGthe reaction mixture was stirred for 15 minutes at −78° C
3. 3
   workup.STIRRINGthe reaction mixture was stirred at room temperature
4. 4
   Промывкаwashed with a saturated aqueous solution of NH4Cl
5. 5
   СушкаThe combined organic phases were dried over MgSO4
6. 6
   Фильтрацияwere filtered
7. 7
   Другоеsolvents were evaporated
8. 8
   ДругоеThe crude mixture was purified by flash chromatography over silica gel

Методика

According to Scheme 16: Butyl lithium 2.5 M (9.9 mmol, 4 mL) was added to a solution of diisopropylamine (9.9 mmol, 1.4 mL) in THF (20 mL) at −78° C. and the reaction mixture was stirred at −78° C. for 5 minutes and then at room temperature. To the resulting LDA solution was added at −78° C. a solution of ethyl 1-(4-methoxybenzyl)-1H-pyrazole-4-carboxylate (7.61 mmol, 1.98 g) in THF (30 mL) and the reaction mixture was stirred for 15 minutes at −78° C. Then N-methoxy-N-methylcyclopropanecarboxamide (9.14 mmol, 1.18 g) in THF (10 mL) was added and the reaction mixture was stirred at room temperature. The reaction mixture was diluted with AcOEt and washed with a saturated aqueous solution of NH4Cl. The combined organic phases were dried over MgSO4, were filtered and solvents were evaporated. The crude mixture was purified by flash chromatography over silica gel using cyclohexane/AcOEt (90:10) as eluent to yield ethyl 3-(cyclopropanecarbonyl)-1-(4-methoxybenzyl)-1H-pyrazole-4-carboxylate (0.74 mmol, 244 mg, 9%).

Источник