ethyl 2-(2,4-dichlorophenyl)-2-oxoacetate

Conditions: temp:25.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: An ethanolic solution of sodium ethylate, obtained from sodium (3.35 g; 0.1457 moles) and dry ethanol (276 ml), kept under stirring in inert atmosphere, was added at 20° C. with a solution of (2,4-dichloro-phenyl)-oxo-acetic acid ethyl ester obtained as described in example 2 (36 g; 0.147 moles), and triethyl phosphonoacetate (34.2 g; 0.152 moles) in dry ethanol (70 ml). The reaction mixture was then brought and kept at reflux for 16-20 hours. After cooling to 25° C., the mixture was poured under stirring into a solution of saturated NaCl (500 ml), ethyl ether was added (150 ml) and the phases were separated. The aqueous phase was extracted again with ethyl ether (150 ml). The joined organic phases were washed with water (100 ml), anhydrified over dry Na2SO4, evaporated to dryness. The thus obtained residue was purified by chromatography (SiO2; hexane/ethyl ether 9/1) to give 24.6 g of (E) 2-(2,4-dichlorophenyl)-butendioic acid diethyl ester (yield 53%) as a colourless oil. obtained at reflux for 16-20 hours the mixture was poured was added (150 ml) the phases were separated The aqueous phase was extracted again with ethyl ether (150 ml) The joined organic phases were washed with water (100 ml) over dry Na2SO4, evaporated to dryness The thus obtained residue was purified by chromatography (SiO2; hexane/ethyl ether 9/1)

Conditions: temp:-70.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: A suspension of magnesium (6.7 g; 0.275 moles) in ethyl ether (125 ml) under stirring and nitrogen flow was added with ethyl bromide (180 mg). A solution of 1,3-dichloro-4-iodobenzene (50 g; 0.183 moles) and ethyl bromide (180 mg) in ethyl ether (100 ml) was dropped in about 1 hour keeping the temperature at 15-20° C. The suspension was stirred for further 2 hours. After decanting the magnesium in excess, the solution was dropped in about 1 hour in a solution of diethyloxalate (29.32 g; 0.2 moles) in ethyl ether (125 ml) cooled to −70° C. At the end of the addition it was stirred at −70° C. for 1 hour, then the temperature was left to rise to 10° C. and the stirring was kept on for another hour. The suspension was added with a saturated solution of NH4Cl (125 ml), the phases were separated and the aqueous one extracted with ethyl acetate (50 ml). The organic phases were washed with a solution of sodium bisulfite and treated with discolouring charcoal. After filtration, the organic solution was distilled under vacuum to give a crude which was purified by chromatography (SiO2; hexane/ethyl ether 9/1) to give 36.2 g of (2,4-dichloro-phenyl)-oxo-acetic acid ethyl ester (yield 80%) as a colourless oil. at 15-20° C The suspension was stirred for further 2 hours After decanting the magnesium in excess, the solution At the end of the addition it was stirred at −70° C. for 1 hour the temperature was left to rise to 10° C. the phases were separated the aqueous one extracted with ethyl acetate (50 ml) The organic phases were washed with a solution of sodium bisulfite treated with discolouring charcoal After filtration the organic solution was distilled under vacuum to give a crude which was purified by chromatography (SiO2; hexane/ethyl ether 9/1)

Conditions: temp:25.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: An ethanolic solution of sodium ethylate, obtained from sodium (3.35 g; 0.1457 moles) and dry ethanol (276 ml), kept under stirring in inert atmosphere, was added at 20° C. with a solution of (2,4-dichloro-phenyl)-oxo-acetic acid ethyl ester obtained as described in example 2 (36 g; 0.147 moles), and triethyl phosphonoacetate (34.2 g; 0.152 moles) in dry ethanol (70 ml). The reaction mixture was then brought and kept at reflux for 16-20 hours. After cooling to 25° C., the mixture was poured under stirring into a solution of saturated NaCl (500 ml), ethyl ether was added (150 ml) and the phases were separated. The aqueous phase was extracted again with ethyl ether (150 ml). The joined organic phases were washed with water (100 ml), anhydrified over dry Na2SO4, evaporated to dryness. The thus obtained residue was purified by chromatography (SiO2; hexane/ethyl ether 9/1) to give 24.6 g of (E) 2-(2,4-dichlorophenyl)-butendioic acid diethyl ester (yield 53%) as a colourless oil. obtained at reflux for 16-20 hours the mixture was poured was added (150 ml) the phases were separated The aqueous phase was extracted again with ethyl ether (150 ml) The joined organic phases were washed with water (100 ml) over dry Na2SO4, evaporated to dryness The thus obtained residue was purified by chromatography (SiO2; hexane/ethyl ether 9/1)

Conditions: temp:-70.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: A suspension of magnesium (6.7 g; 0.275 moles) in ethyl ether (125 ml) under stirring and nitrogen flow was added with ethyl bromide (180 mg). A solution of 1,3-dichloro-4-iodobenzene (50 g; 0.183 moles) and ethyl bromide (180 mg) in ethyl ether (100 ml) was dropped in about 1 hour keeping the temperature at 15-20° C. The suspension was stirred for further 2 hours. After decanting the magnesium in excess, the solution was dropped in about 1 hour in a solution of diethyloxalate (29.32 g; 0.2 moles) in ethyl ether (125 ml) cooled to −70° C. At the end of the addition it was stirred at −70° C. for 1 hour, then the temperature was left to rise to 10° C. and the stirring was kept on for another hour. The suspension was added with a saturated solution of NH4Cl (125 ml), the phases were separated and the aqueous one extracted with ethyl acetate (50 ml). The organic phases were washed with a solution of sodium bisulfite and treated with discolouring charcoal. After filtration, the organic solution was distilled under vacuum to give a crude which was purified by chromatography (SiO2; hexane/ethyl ether 9/1) to give 36.2 g of (2,4-dichloro-phenyl)-oxo-acetic acid ethyl ester (yield 80%) as a colourless oil. at 15-20° C The suspension was stirred for further 2 hours After decanting the magnesium in excess, the solution At the end of the addition it was stirred at −70° C. for 1 hour the temperature was left to rise to 10° C. the phases were separated the aqueous one extracted with ethyl acetate (50 ml) The organic phases were washed with a solution of sodium bisulfite treated with discolouring charcoal After filtration the organic solution was distilled under vacuum to give a crude which was purified by chromatography (SiO2; hexane/ethyl ether 9/1)

Conditions: temp:25.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: An ethanolic solution of sodium ethylate, obtained from sodium (3.35 g; 0.1457 moles) and dry ethanol (276 ml), kept under stirring in inert atmosphere, was added at 20° C. with a solution of (2,4-dichloro-phenyl)-oxo-acetic acid ethyl ester obtained as described in example 2 (36 g; 0.147 moles), and triethyl phosphonoacetate (34.2 g; 0.152 moles) in dry ethanol (70 ml). The reaction mixture was then brought and kept at reflux for 16-20 hours. After cooling to 25° C., the mixture was poured under stirring into a solution of saturated NaCl (500 ml), ethyl ether was added (150 ml) and the phases were separated. The aqueous phase was extracted again with ethyl ether (150 ml). The joined organic phases were washed with water (100 ml), anhydrified over dry Na2SO4, evaporated to dryness. The thus obtained residue was purified by chromatography (SiO2; hexane/ethyl ether 9/1) to give 24.6 g of (E) 2-(2,4-dichlorophenyl)-butendioic acid diethyl ester (yield 53%) as a colourless oil. obtained at reflux for 16-20 hours the mixture was poured was added (150 ml) the phases were separated The aqueous phase was extracted again with ethyl ether (150 ml) The joined organic phases were washed with water (100 ml) over dry Na2SO4, evaporated to dryness The thus obtained residue was purified by chromatography (SiO2; hexane/ethyl ether 9/1)

Conditions: temp:-70.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: A suspension of magnesium (6.7 g; 0.275 moles) in ethyl ether (125 ml) under stirring and nitrogen flow was added with ethyl bromide (180 mg). A solution of 1,3-dichloro-4-iodobenzene (50 g; 0.183 moles) and ethyl bromide (180 mg) in ethyl ether (100 ml) was dropped in about 1 hour keeping the temperature at 15-20° C. The suspension was stirred for further 2 hours. After decanting the magnesium in excess, the solution was dropped in about 1 hour in a solution of diethyloxalate (29.32 g; 0.2 moles) in ethyl ether (125 ml) cooled to −70° C. At the end of the addition it was stirred at −70° C. for 1 hour, then the temperature was left to rise to 10° C. and the stirring was kept on for another hour. The suspension was added with a saturated solution of NH4Cl (125 ml), the phases were separated and the aqueous one extracted with ethyl acetate (50 ml). The organic phases were washed with a solution of sodium bisulfite and treated with discolouring charcoal. After filtration, the organic solution was distilled under vacuum to give a crude which was purified by chromatography (SiO2; hexane/ethyl ether 9/1) to give 36.2 g of (2,4-dichloro-phenyl)-oxo-acetic acid ethyl ester (yield 80%) as a colourless oil. at 15-20° C The suspension was stirred for further 2 hours After decanting the magnesium in excess, the solution At the end of the addition it was stirred at −70° C. for 1 hour the temperature was left to rise to 10° C. the phases were separated the aqueous one extracted with ethyl acetate (50 ml) The organic phases were washed with a solution of sodium bisulfite treated with discolouring charcoal After filtration the organic solution was distilled under vacuum to give a crude which was purified by chromatography (SiO2; hexane/ethyl ether 9/1)