Ethyl 3,5-dichloro-4-fluorobenzoate

Conditions: temp:80.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: Potassium carbonate (36 g, 0.26 moles) was added to a stirred mixture of 3,5-dichloro-4-fluorobenzoic acid (27.6 g, 0.13 moles), ethyl iodide (41.2 g-0.26 moles) and dry dimethylformamide (300 ml) under nitrogen. The reaction was heated to 80° C. for 6 hours. The dimethylformamide was removed in vacuo and the residue treated with water (200 ml) acidified with dilute hydrochloric acid and extracted with ethylacetate (2×250 ml). The organic layer was washed with water, dried over magnesium sulphate and evaporated in vacuo, to give an orange oil which was purified by chromatography on silica, using a 4:1 mixture of petrol and diethylether as eluent. The pink oil obtained crystallised on standing, and washing with ice-cold 40-60 petrol gave white crystals of ethyl 3,5-dichloro-4-fluorobenzoate (29 g). The dimethylformamide was removed in vacuo the residue treated with water (200 ml) extracted with ethylacetate (2×250 ml) The organic layer was washed with water dried over magnesium sulphate evaporated in vacuo to give an orange oil which was purified by chromatography on silica a 4:1 mixture of petrol and diethylether as eluent The pink oil obtained crystallised washing with ice-cold 40-60 petrol

Conditions: temp:80.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: Potassium carbonate (36 g, 0.26 moles) was added to a stirred mixture of 3,5-dichloro-4-fluorobenzoic acid (27.6 g, 0.13 moles), ethyl iodide (41.2 g-0.26 moles) and dry dimethylformamide (300 ml) under nitrogen. The reaction was heated to 80° C. for 6 hours. The dimethylformamide was removed in vacuo and the residue treated with water (200 ml) acidified with dilute hydrochloric acid and extracted with ethylacetate (2×250 ml). The organic layer was washed with water, dried over magnesium sulphate and evaporated in vacuo, to give an orange oil which was purified by chromatography on silica, using a 4:1 mixture of petrol and diethylether as eluent. The pink oil obtained crystallised on standing, and washing with ice-cold 40-60 petrol gave white crystals of ethyl 3,5-dichloro-4-fluorobenzoate (29 g). The dimethylformamide was removed in vacuo the residue treated with water (200 ml) extracted with ethylacetate (2×250 ml) The organic layer was washed with water dried over magnesium sulphate evaporated in vacuo to give an orange oil which was purified by chromatography on silica a 4:1 mixture of petrol and diethylether as eluent The pink oil obtained crystallised washing with ice-cold 40-60 petrol

Conditions: temp:80.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: Potassium carbonate (36 g, 0.26 moles) was added to a stirred mixture of 3,5-dichloro-4-fluorobenzoic acid (27.6 g, 0.13 moles), ethyl iodide (41.2 g-0.26 moles) and dry dimethylformamide (300 ml) under nitrogen. The reaction was heated to 80° C. for 6 hours. The dimethylformamide was removed in vacuo and the residue treated with water (200 ml) acidified with dilute hydrochloric acid and extracted with ethylacetate (2×250 ml). The organic layer was washed with water, dried over magnesium sulphate and evaporated in vacuo, to give an orange oil which was purified by chromatography on silica, using a 4:1 mixture of petrol and diethylether as eluent. The pink oil obtained crystallised on standing, and washing with ice-cold 40-60 petrol gave white crystals of ethyl 3,5-dichloro-4-fluorobenzoate (29 g). The dimethylformamide was removed in vacuo the residue treated with water (200 ml) extracted with ethylacetate (2×250 ml) The organic layer was washed with water dried over magnesium sulphate evaporated in vacuo to give an orange oil which was purified by chromatography on silica a 4:1 mixture of petrol and diethylether as eluent The pink oil obtained crystallised washing with ice-cold 40-60 petrol

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

Procedure: Into a three-necked 50 ml flask equipped with a condenser and a stirrer, 1.9 g (33 mmol) of spray-dried potassium fluoride (purchased from Laporte Industry), 1.1 g (2.5 mmol) of tetraphenyl phosphonium bromide, 0.7 g (2.5 mmol) of 18-crown-6 and 6.4 g (25 mmol) of ethyl 3,4,5-trichlorobenzoate were introduced, and the mixture was heated in an oil bath and reacted under a nitrogen atmosphere at 210° C. for 2 hours. The reactor was cooled, and the mixture was diluted with 40 ml of toluene. Inorganic salts were filtered off, and toluene was concentrated to give the residue, which was distilled under reduced pressure to obtain 3.4 g of ethyl 3,5-dichloro-4-fluorobenzoate. The yield was 57%. The physical properties are shown below. Into a three-necked 50 ml flask equipped with a condenser and a stirrer the mixture was heated in an oil bath reacted under a nitrogen atmosphere at 210° C. for 2 hours The reactor was cooled Inorganic salts were filtered off toluene was concentrated to give the residue, which was distilled under reduced pressure

Conditions: temp:80.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: Potassium carbonate (36 g, 0.26 mol) was added to a stirred mixture of 3,5-dichloro-4-fluorobenzoic acid (27.6 g, 0.13 mol), ethyl iodide (41.2 g- 0.26 moles) and dry dimethylformamide (300 ml) under nitrogen. The reaction was heated to 80° C. for 6 hours. The dimethylformamide was removed in vacuo and the residue treated with water (200 ml) acidified with dilute hydrochloric acid and extracted with ethylacetate (2×250 ml). The organic layer was washed with water, dried over magnesium sulphate and evaporated in vacuo, to give an orange oil which was purified by chromatography on silica, using a 4:1 mixture of petrol and diethylether as eluent. The pink oil obtained crystallised on standing, and washing with ice-cold 40-60 petrol gave white crystals of ethyl 3,5-dichloro-4-fluorobenzoate (29 g). The dimethylformamide was removed in vacuo the residue treated with water (200 ml) extracted with ethylacetate (2×250 ml) The organic layer was washed with water dried over magnesium sulphate evaporated in vacuo to give an orange oil which was purified by chromatography on silica a 4:1 mixture of petrol and diethylether as eluent The pink oil obtained crystallised washing with ice-cold 40-60 petrol