ethyl 2,2-dibromoacetate

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:100.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: A mixture of 11.0 g of 3,4-dichloro-1,2-benzenediol, 15.38 g of potassium carbonate, 27 g of ethyl dibromoacetate and 100 ml of dimethylformamide is stirred at 100° C. under argon gas atmosphere for 4 hours. The reaction mixture is evaporated to remove solvent and ethyl acetate and water is added to the residue. The organic layer is separated, washed with water, dried and evaporated to remove solvent. The residue is purified by silica gel column chromatography to give 10.75 g of ethyl 4,5-dichloro-1,3-benzodioxole-2carboxylate. The reaction mixture is evaporated to remove solvent and ethyl acetate and water is added to the residue The organic layer is separated washed with water dried evaporated to remove solvent The residue is purified by silica gel column chromatography

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: To a solution of 2.0 g of (1-methylpyrazol-5-yl)-(2,3-dichloro-4,5-dihydroxyphenyl)-methanone in 22 ml of dimethylformamide are added 2.12 g of powdered potassium carbonate and 3.7 g of ethyl dibromoacetate, and the mixture is stirred at 90° to 100° C. under argon gas atmosphere for 2 hours. After cooling, the mixture is poured into ice-water and the mixture is extracted with ethyl acetate. The extract is washed with an aqueous saturated sodium chloride solution, dried and evaporated to remove solvent under reduced pressure. The residue is purified by silica gel column chromatography (solvent; n-hexane-ethyl acetate) to give 1.64 g of ethyl 4,5-dichloro-6-(1-methyl-5-pyrazolylcarbonyl)-1,3-benzodioxole-2-carboxylate. After cooling the mixture is extracted with ethyl acetate The extract is washed with an aqueous saturated sodium chloride solution dried evaporated to remove solvent under reduced pressure The residue is purified by silica gel column chromatography (solvent; n-hexane-ethyl acetate)

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: To a solution of 2.0 g of (1-methylpyrazol-5-yl)-(2,3-dichloro-4,5-dihydroxyphenyl)-methanone in 22 ml of dimethylformamide are added 2.12 g of powdered potassium carbonate and 3.7 g of ethyl dibromoacetate, and the mixture is stirred at 90° to 100° C. under argon gas atmosphere for 2 hours. After cooling, the mixture is poured into ice-water and the mixture is extracted with ethyl acetate. The extract is washed with an aqueous saturated sodium chloride solution, dried and evaporated to remove solvent under reduced pressure. The residue is purified by silica gel column chromatography (solvent; n-hexane-ethyl acetate) to give 1.64 g of ethyl 4,5-dichloro-6-(1-methyl-5-pyrazolylcarbonyl)-1,3-benzodioxole-2-carboxylate. After cooling the mixture is extracted with ethyl acetate The extract is washed with an aqueous saturated sodium chloride solution dried evaporated to remove solvent under reduced pressure The residue is purified by silica gel column chromatography (solvent; n-hexane-ethyl acetate)

Conditions: temp:100.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: A mixture of 11.0 g of 3,4-dichloro-1,2-benzenediol, 15.38 g of potassium carbonate, 27 g of ethyl dibromoacetate and 100 ml of dimethylformamide is stirred at 100° C. under argon gas atmosphere for 4 hours. The reaction mixture is evaporated to remove solvent and ethyl acetate and water is added to the residue. The organic layer is separated, washed with water, dried and evaporated to remove solvent. The residue is purified by silica gel column chromatography to give 10.75 g of ethyl 4,5-dichloro-1,3-benzodioxole-2-carboxylate. The reaction mixture is evaporated to remove solvent and ethyl acetate and water is added to the residue The organic layer is separated washed with water dried evaporated to remove solvent The residue is purified by silica gel column chromatography

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: To a solution of 2.0 g of (1-methylpyrazol-5-yl)-(2,3-dichloro-4,5-dihydroxyphenyl)-methanone in 22 ml of dimethylformamide are added 2.12 g of powdered potassium carbonate and 3.7 g of ethyl dibromoacetate, and the mixture is stirred at 90° to 100° C. under argon gas atmosphere for 2 hours. After cooling, the mixture is poured into ice-water and the mixture is extracted with ethyl acetate. The extract is washed with an aqueous saturated sodium chloride solution, dried and evaporated to remove solvent under reduced pressure. The residue is purified by silica gel column chromatography (solvent; n-hexane-ethyl acetate) to give 1.64 g of ethyl 4,5-dichloro-6-(1-methyl-5-pyrazolylcarbonyl)-1,3-benzodioxole-2-carboxylate. Yield: 63% After cooling the mixture is extracted with ethyl acetate The extract is washed with an aqueous saturated sodium chloride solution dried evaporated to remove solvent under reduced pressure The residue is purified by silica gel column chromatography (solvent; n-hexane-ethyl acetate)

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: To a solution of 2.0 g of (1-methylpyrazol-5-yl)-(2,3-dichloro-4,5-dihydroxyphenyl)-methanone in 22 ml of dimethylformamide are added 2.12 g of powdered potassium carbonate and 3.7 g of ethyl dibromoacetate, and the mixture is stirred at 90° to 100° C. under argon gas atmosphere for 2 hours. After cooling, the mixture is poured into ice-water and the mixture is extracted with ethyl acetate. The extract is washed with an aqueous saturated sodium chloride solution, dried and evaporated to remove solvent under reduced pressure. The residue is purified by silica gel column chromatography (solvent; n-hexane-ethyl acetate) to give 1.64 g of ethyl 4,5-dichloro-6-(1-methyl-5-pyrazolylcarbonyl)-1,3-benzodioxole-2-carboxylate. Yield: 63% After cooling the mixture is extracted with ethyl acetate The extract is washed with an aqueous saturated sodium chloride solution dried evaporated to remove solvent under reduced pressure The residue is purified by silica gel column chromatography (solvent; n-hexane-ethyl acetate)

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:0.00; pressure:0.00; stir: