تفاعل #47218

معادلة التفاعل

methyl 2-chloro-3,4-dihydroxybenzoate

KF

Dibromomethane

→

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

المردود 42.0%

المذيبات

DMF

water

ظروف التفاعل

المعالجة

1. 1
   درجة الحرارةthe mixture was heated to 120° C. for 4 h
2. 2
   درجة الحرارةThe mixture was cooled down to room temperature
3. 3
   استخلاصextracted with ethyl ether
4. 4
   غسيلThe combined ether layers were washed with 1M NaOH, water, brine
5. 5
   تجفيفdried over anhydrous Na2SO4
6. 6
   ترشيحfiltered
7. 7
   أخرىsolvent removed under vacuum
8. 8
   أخرىThe crude product was absorbed onto silica
9. 9
   أخرىpurified by flash column (silicagel, hexane

الإجراء التجريبي

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.

المصدر