تفاعل #1377689

معادلة التفاعل

bromine

product

methyl 4-acetyl-2,6-dichlorophenoxyacetate

→

methyl 4-bromoacetyl-2,6- dichlorophenoxyacetate

المذيبات

chloroform

chloroform

ظروف التفاعل

المعالجة

1. 1
   أخرىThe solvent was removed in vacuo
2. 2
   أخرىthe residual oil purified by flash chromatography on silica
3. 3
   غسيلeluting with dichloromethane
4. 4
   أخرىto give a crystalline solid
5. 5
   أخرىRecrystallisation from methanol

الإجراء التجريبي

A solution of bromine (0.77 ml) in chloroform (10 ml) was added dropwise over 15 minutes to a stirred solution of the product from step i) (4.16 g) in chloroform (40 ml) at 25° C. The temperature was raised to 40° C. for 1 hour and then stirring continued for a further 18 hours at ambient temperature. The solvent was removed in vacuo and the residual oil purified by flash chromatography on silica, eluting with dichloromethane, to give a crystalline solid. Recrystallisation from methanol gave methyl 4-bromoacetyl-2,6- dichlorophenoxyacetate, 1.88 g, as white crystals: m.p. 89°-90° C.; NMR (d6DMSO) δ 8.06(2H,s), 4.93(2H,s), 4.82(2H,s), 3.72(3H,s); m/e 355/357 (M+H)+, 1 Br pattern; calculated for C11H9BrCl2O4 : C, 37.1; H, 2.3. found: C, 36.8; H, 2.4%.

المصدر