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ChemicalBook CAS DataBase List DIETHYL 2-CHLORO-6-FLUOROPHENYL MALONATE
190521-88-1

DIETHYL 2-CHLORO-6-FLUOROPHENYL MALONATE synthesis

2synthesis methods
-

Yield:-

Reaction Conditions:

with hydrogenchloride;sodium ethanolate;magnesium in water;

Steps:

1 Preparation of diethyl 2-chloro-6-fluorophenylmalonate

EXAMPLE 1 Preparation of diethyl 2-chloro-6-fluorophenylmalonate A mixture of magnesium (27 g), dimethoxymethane (40 ml) and dibromoethane (0.5 ml) is heated to 43° C. under stirring. After 5 minutes a mixture of 2-chloro-6-fluorobenzylchloride (4 g) and dimethoxymethane (16 ml) is added to initiate the reaction and stirred for 20 minutes. Within 2 hours a mixture of 2-chloro-6-fluorobenzylchloride (96 g) and dimethoxymethane (384 ml) is dosed to the reaction mixture under stirring at 42° to 44° C. The mixture is kept under reflux with stirring for 1.5 hours. Upon cooling down to 30° C. the reaction mixture is dosed to diethoxycarbonate (340 ml) at -8° to -14° C. within 0.5 hours. The reaction mixture is held at -10° C. for 2 hours. Upon warming up to 1° C. the reaction mixture is neutralized with a mixture of concentrated HCl (60 ml) and water (150 ml). The phases are separated and the organic phase is transferred to another reactor. The reaction mixture is concentrated by distillation. Sodium ethylate (46 g) is added after cooling down to 75° C. The reaction mixture is heated to 120° C. and the remaining dimethoxymethane and the formed ethanol is distilled off. Upon cooling down to 20° C. the reaction mixture is neutralized with a mixture of concentrated HCl (60 ml) and water (150 ml). The phases are separated and the organic phase is dried with magnesium sulfate and concentrated in vacuo to yield the crude product (128 g /80% yield).

References:

US5750766,1998,A

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