heptane-3,5-dione

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

Procedure: A suspension of 0.5 mole of 6-(4-hydroxyphenyl)hexyl bromide [pepared from 6-(4-methoxyphenyl)hexyl bromide and boron tribromide in methylene dichloride according to the procedure of Example 42f], 0.125 mole of potassium iodide, 1.15 moles of 3,5-heptanedione and 1.05 moles of powdered anhydrous potassium carbonate (dried in vacuo for two hours) in 2 liters of acetone is stirred at reflux for 24 hours. One liter of solvent is distilled off and the remainder of the reaction mixture is poured with stirring into a solution of 4 liters of ice-water containing 160 ml. of concentrated hydrochloric acid. The separated product is extracted with ether and the ether extracts washed with saturated sodium chloride solution and dried over anhydrous magnesium sulfate. The ether is distilled off in vacuo and the excess 3,5-heptanedione removed at 70° C. (0.8 mm.) in a rotary evaporator. The residual product is crystallized from isopropyl alcohol-pentane to give 4-[6-(4-hydroxyphenyl)hexyl]-3,5-heptanedione. at reflux for 24 hours One liter of solvent is distilled off the remainder of the reaction mixture is poured with stirring into a solution of 4 liters of ice-water containing 160 ml The separated product is extracted with ether the ether extracts washed with saturated sodium chloride solution dried over anhydrous magnesium sulfate The ether is distilled off in vacuo the excess 3,5-heptanedione removed at 70° C. (0.8 mm.) in a rotary evaporator The residual product is crystallized from isopropyl alcohol-pentane

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

Procedure: A solution of 15 g. of the lithium salt of 3,5-heptanedione (prepared as described in Example 8 below) in 100 ml. of tetramethylurea was stirred under nitrogen at room temperature, and 10 g. of 3-ethyl-6-(3,4-methylenedioxyphenyl)-3-hexenyl iodide (Preparation D1) was added. The reaction mixture was stirred for forty-eight hours, then concentrated to remove the solvent, and the residue slurried in ether and treated with excess glacial acetic acid. Water was added, the ether layer separated, washed with water and concentrated. The residue was distilled in a molecular still to remove volatile material at 110° C. (0.001 mml.), and the non-volatile residue was chromatographed on 10 g. of activated magnesium silicate in benzene solution and eluted with ethyl acetate to give 4-[3-ethyl-6-(3,4-methylenedioxyphenyl)-3-hexenyl]-3,5-heptanedione as a yellow oil. concentrated to remove the solvent the residue slurried in ether and treated with excess glacial acetic acid Water was added the ether layer separated washed with water concentrated The residue was distilled in a molecular still to remove volatile material at 110° C. (0.001 mml.) the non-volatile residue was chromatographed on 10 g of activated magnesium silicate in benzene solution and eluted with ethyl acetate

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

Procedure: A solution of 16.1 g (0.126 m) of 3,5-heptanedione in 50 ml of dimethylformamide was added during 15 minutes to a stirred suspension of 1.2 g of lithium hydride in 100 ml of dimethylformamide. The mixture was stirred one hour at room temperature and then a solution of 27.6 g (0.0619 m) of 1,4-bis(3-iodopropyloxy)benzene in 100 ml of dimethylformaide was added. The reaction mixture was heated at 60°-70° C. for about 16 hours and then concentrated in vacuo. The residue was distilled to remove volatiles (150° C., 0.05 mm) and chromatographed on 400 g of silica with chloroform:acetonitrile 95:5. The product was distilled at 250° C. (0.02 mm) and crystallized from ether to give 4.4 g of 1,4-bis(4,4-dipropionylbutyloxy)benzene, m.p. 57°-58° C. The reaction mixture was heated at 60°-70° C. for about 16 hours concentrated in vacuo The residue was distilled to remove volatiles (150° C., 0.05 mm) chromatographed on 400 g of silica with chloroform:acetonitrile 95:5 The product was distilled at 250° C. (0.02 mm) crystallized from ether

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

Procedure: Chlorotrimethylsilane (29.7 ml, 0.234 mol) was added dropwise to a stirred pale yellow solution of tetrabutylammonium bromide (1.26 g, 3.9 mmol) in dry acetonitrile (116 ml) at room temperature under nitrogen. The resulting solution was cooled in ice and 3,5-heptanedione (10.6 ml, 78.0 mmol) and then dry dimethylsulphoxide (16.6 ml, 0.234 mol) were added dropwise over 5 minutes producing a yellow solution which was allowed to warm slowly to room temperature, with stirring, over 4 hours. The mixture was diluted with water (1 litre), stirred for 10 min and then extracted with ether (1×500 ml, 2×250 ml). The combined ether layers were dried over magnesium sulphate, filtered and concentrated under reduced pressure to leave a yellow oil. The crude product was purified by distillation under reduced pressure to afford the title compound (5.5 g) as a pale yellow oil, b.p. 102-105° C./54 mmHg containing ca. 10% 4,4-dichloro-3,5-heptanedione as estimated by microanalysis. The resulting solution was cooled in ice producing a yellow solution which stirred for 10 min extracted with ether (1×500 ml, 2×250 ml) The combined ether layers were dried over magnesium sulphate filtered concentrated under reduced pressure to leave a yellow oil The crude product was purified by distillation under reduced pressure