반응 #167140

반응 방정식

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

수율 59.0%

용매

THF

ethyl acetate

THF

반응 조건

후처리

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

실험 절차

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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