반응 #47218

반응 방정식

methyl 2-chloro-3,4-dihydroxybenzoate

KF

Dibromomethane

→

methyl 4-chlorobenzo[d][1,3]dioxole-5-carboxylate

수율 42.0%

용매

DMF

water

반응 조건

후처리

1. 1
   온도the mixture was heated to 120° C. for 4 h
2. 2
   온도The mixture was cooled down to room temperature
3. 3
   추출extracted with ethyl ether
4. 4
   세척The combined ether layers were washed with 1M NaOH, water, brine
5. 5
   건조dried over anhydrous Na2SO4
6. 6
   여과filtered
7. 7
   기타solvent removed under vacuum
8. 8
   기타The crude product was absorbed onto silica
9. 9
   기타purified by flash column (silicagel, hexane

실험 절차

To a heavy walled vial containing methyl 2-chloro-3,4-dihydroxybenzoate (899.8 mg, 4.4 mmol, 1 equiv.) in 13 mL DMF was added KF (1.29 g, 22.2 mmol, 5 equiv.) and the mixture was stirred at room temperature for 30 min. Dibromomethane (0.375 mL, 5.3 mmol, 1.2 equiv.) was added and the mixture was heated to 120° C. for 4 h. The mixture was cooled down to room temperature, diluted with water, and extracted with ethyl ether. The combined ether layers were washed with 1M NaOH, water, brine, dried over anhydrous Na2SO4, filtered and solvent removed under vacuum. The crude product was absorbed onto silica and purified by flash column (silicagel, hexane:ethyl acetate 8 Å to give 395.8 mg (42%) of methyl 4-chlorobenzo[d][1,3]dioxole-5-carboxylate as a colorless crystalline solid. See Tetrahedron Lett. 38: 3361-3364 (1978); U.S. Patent Appl. Publication No. 20050009867.

출처