반응 #1833219

반응 방정식

1,1,2-Trichloro-1,2,2-trifluoroethane

2,2,6,6-Tetramethylpiperidine

n-butyllithium

NH4Cl

5-Bromo-2,2-difluorobenzo[d][1,3]dioxole

→

title compound

수율 28.1%

5-Bromo-4-chloro-2,2-difluorobenzo[d][1,3]dioxole

수율 28.1%

용매

water

diethyl ether

tetrahydrofuran

반응 조건

후처리

1. 1
   workup.STIRRINGthe mixture was stirred for 2 h at −75° C
2. 2
   workup.STIRRINGstirring
3. 3
   workup.WAITwas continued for 1.5 h
4. 4
   세척The ether phase was washed with saturated NaCl (10 mL)
5. 5
   건조dried (Na2SO4)
6. 6
   기타evaporated under vacuum
7. 7
   기타The residue was purified by chromatography on silica with hexane
8. 8
   기타repurified by reverse-phase

실험 절차

2,2,6,6-Tetramethylpiperidine (2.1 mL, 1.8 g, 12 mmol) was dissolved in dry tetrahydrofuran (15 mL), cooled to −75° C. and treated with n-butyllithium (n-BuLi, 2.5 M; 4.8 mL, 12 mmol), and the mixture was stirred for 30 min at −75° C. 5-Bromo-2,2-difluorobenzo[d][1,3]dioxole (2.0 g, 8.4 mmol) was added, and the mixture was stirred for 2 h at −75° C. 1,1,2-Trichloro-1,2,2-trifluoroethane (2.4 mL, 3.8 g, 20 mmol) was added and stirring was continued for 1.5 h. Saturated NH4Cl (10 mL) was added, and the mixture was shaken with diethyl ether (30 mL) and water (20 mL). The ether phase was washed with saturated NaCl (10 mL), dried (Na2SO4) and evaporated under vacuum. The residue was purified by chromatography on silica with hexane and then repurified by reverse-phase HPLC using 75% acetonitrile to give the title compound as a clear liquid (640 mg, 28%): 1H NMR (400 MHz, CDCl3) δ 7.38 (dd, J=8.5, 5.1 Hz, 1H), 6.90 (dd, J=9.0, 4.7 Hz, 1H); EIMS m/z 332.

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