Реакция #167140

Уравнение реакции

1-Iodo-3,3,3-trifluoropropane

2-isopropyl-3,6-dimethoxy-2,5-dihydro-pyrazine

n-butyllithium

→

2-Isopropyl-3,6-dimethoxy-5-(3,3,3-trifluoro-propyl)-2,5-dihydro-pyrazine

Выход 59.0%

Растворители

THF

ethyl acetate

THF

Условия реакции

Обработка

1. 1
   workup.STIRRINGThe resulting solution was stirred at −78° C. for 5 hours
2. 2
   Температураwarmed to room temperature
3. 3
   ПромывкаThe organic layer was washed successively with saturated aqueous NH4Cl solution, water and brine
4. 4
   СушкаThe organic layer was then dried (MgSO4)
5. 5
   Концентрированиеconcentrated
6. 6
   Другоеpurified by flash chromatography

Методика

To a stirred solution of 2-isopropyl-3,6-dimethoxy-2,5-dihydro-pyrazine (1 mL, 5.58 mmol) in THF (13.5 mL) under argon at −78° C. was added a solution of n-butyllithium (2.5 M, 2.3 mL, 5.75 mmol). The solution was stirred at −78° C. for 30 minutes. A solution of 1-Iodo-3,3,3-trifluoropropane (925 μL, 5.87 mmol) in THF (11.5 mL) was added slowly. The resulting solution was stirred at −78° C. for 5 hours, warmed to room temperature and diluted with ethyl acetate. The organic layer was washed successively with saturated aqueous NH4Cl solution, water and brine. The organic layer was then dried (MgSO4), concentrated and purified by flash chromatography to yield 2-Isopropyl-3,6-dimethoxy-5-(3,3,3-trifluoro-propyl)-2,5-dihydro-pyrazine (915 mg, 59%). 1H-NMR: 400 MHz, (CDCl3) δ: 4.04-3.99 (m, 1H), 3.98-3.95 (m, 1H), 3.71 (s, 3H), 3.68 (s, 3H), 2.29-2.20 (m, 1H), 2.18-2.04 (m, 3H), 1.94-1.84 (m, 1H), 1.03 (d, J=6.9 Hz, 3H), 0.71 (d, J=6.8 Hz, 3H) ppm.

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