1,2-bis(4-chlorophenyl)ethanone

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

Procedure: 4,4'-Dichlorodeoxybenzoin can be prepared by heating 4-chlorophenylacetic acid (85g) in thionyl chloride (59.5g) under reflux for 2.5 hours to yield 4-chlorophenylacetyl chloride (45.5g) which is subsequently dissolved in chlorobenzene (30g) and added dropwise with cooling to a stirred aluminium chloride (73g). The resultant mixture is cooled and stirred for a further 0.5 hours and then heated at 100° for one hour. The mixture was again cooled and poured into a mixture of conc. hyrochloric acid (200ml) and ice (1 liter) precipitate on standing crude 4,4'-dichlorodeoxybenzoin which on recrystallisation from methanol has a melting point of 115°-116°. under reflux for 2.5 hours

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

Procedure: 4,4'-Dichlorodeoxybenzoin can be prepared by heating 4-chlorophenylacetic acid (85g) in thionyl chloride (59.5g) under reflux for 2.5 hours to yield 4-chlorophenylacetyl chloride (45.5g) which is subsequently dissolved in chlorobenzene (30g) and added dropwise with cooling to a stirred aluminium chloride (73g). The resultant mixture is cooled and stirred for a further 0.5 hours and then heated at 100° for one hour. The mixture was again cooled and poured into a mixture of conc. hyrochloric acid (200ml) and ice (1 liter) precipitate on standing crude 4,4'-dichlorodeoxybenzoin which on recrystallisation from methanol has a melting point of 115°-116°. under reflux for 2.5 hours

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

Procedure: The benzoin starting material can be prepared by adding bromine (18.1g) dropwise to a stirred solution of 4,4'-dichlorodeoxybenzoin (30g) in dry diethylether (400ml). The solution is stirred for a further hour and evaporated to provide crude α-bromo-4,4'-dichlorodeoxybenzoin (40g) which when recrystallised from methanol has a melting point of 81°-83°. evaporated

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

Procedure: The benzoin starting material can be prepared by adding bromine (18.1g) dropwise to a stirred solution of 4,4'-dichlorodeoxybenzoin (30g) in dry diethylether (400ml). The solution is stirred for a further hour and evaporated to provide crude α-bromo-4,4'-dichlorodeoxybenzoin (40g) which when recrystallised from methanol has a melting point of 81°-83°. evaporated

Conditions: temp:0.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: A solution of 1,2-di(4-chlorophenyl)ethan-1-one (known compound) and sodium borohydride in methanol is stirred at ambient temperature for about three hours. After this time, the reaction mixture is cooled, and water is carefully added to destroy excess sodium borohydride. The mixture is cooled to 0° C. and neutralized with concentrated hydrochloric acid. The mixture is concentrated under reduced pressure to remove some of the methanol. The concentrate is taken up in ethyl acetate and washed with an aqueous solution saturated with sodium chloride. The organic layer is dried with sodium sulfate, filtered, and concentrated under reduced pressure, yielding the subject compound. After this time, the reaction mixture is cooled to destroy excess sodium borohydride The mixture is concentrated under reduced pressure to remove some of the methanol washed with an aqueous solution saturated with sodium chloride The organic layer is dried with sodium sulfate filtered concentrated under reduced pressure yielding the subject compound

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

Procedure: 4,4'-Dichlorodeoxybenzoin can be prepared by heating 4-chlorophenylacetic acid (85g) in thionyl chloride (59.5g) under reflux for 2.5 hours to yield 4-chlorophenylacetyl chloride (45.5g) which is subsequently dissolved in chlorobenzene (30g) and added dropwise with cooling to a stirred aluminium chloride (73g). The resultant mixture is cooled and stirred for a further 0.5 hours and then heated at 100° for one hour. The mixture was again cooled and poured into a mixture of conc. hyrochloric acid (200ml) and ice (1 liter) precipitate on standing crude 4,4'-dichlorodeoxybenzoin which on recrystallisation from methanol has a melting point of 115°-116°. under reflux for 2.5 hours

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

Procedure: The benzoin starting material can be prepared by adding bromine (18.1g) dropwise to a stirred solution of 4,4'-dichlorodeoxybenzoin (30g) in dry diethylether (400ml). The solution is stirred for a further hour and evaporated to provide crude α-bromo-4,4'-dichlorodeoxybenzoin (40g) which when recrystallised from methanol has a melting point of 81°-83°. evaporated

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

Procedure: The dione product was obtained using the same synthetic methods as shown in Example 25, step 6, using 1,2-bis(4-chlorophenyl)ethanone (2.12 g, 8.00 mmol, 1.00 equiv) and SeO2 (5.11 g, 46.0 mmol, 5.75 equiv) as reactants. The solution was allowed to react, with stifling, for 2 hr at 120° C., then diluted with ethyl acetate, washed with saturated aqueous NaCl, and concentrated under vacuum. This afforded 2.19 g (crude) of 1,2-bis(4-chlorophenyl)ethane-1,2-dione as a yellow solid. The dione product was obtained to react washed with saturated aqueous NaCl concentrated under vacuum

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

Procedure: The diaryl product was obtained using the same synthetic methods as shown in Example 25, step 5, using 2-(4-chlorophenyl)acetic acid (5 g, 29.2 mmol) and chlorobenzene (10.31 g, 91.2 mmol, 2.85 equiv) as reactants. The reaction was quenched by the addition of water/ice. The residue was dissolved in 3% HCl, extracted with 3×20 mL of dichloromethane, and the organic layers combined and concentrated under vacuum. Purification via silica gel column (ethyl acetate/petroleum ether (1:100)) yielded 4.63 g (54%) of 1,2-bis(4-chlorophenyl)ethanone as a white solid. The reaction was quenched by the addition of water/ice The residue was dissolved in 3% HCl extracted with 3×20 mL of dichloromethane concentrated under vacuum Purification via silica gel column (ethyl acetate/petroleum ether (1:100))

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

Procedure: 1.33 g (5 mmol) of 4'-chloro-2-(4-chlorophenyl)acetophenone was dissolved in 25 ml of ethanol, and 1.25 g (25 mmol) of hydrazine monohydrate was added thereto. The mixture was refluxed under heating for 2 hours. After completion of the reaction, ethanol was distilled off under reduced pressure, and water was added to the residue. The mixture was extracted with dichloromethane. The extract was dried over anhydrous sodium sulfate. Then, the solvent was distilled off to obtain 1.44 g of [4'-chloro-2-(4-chlorophenyl)acetophenone]hydrazone as a yellow oily substance. The mixture was refluxed under heating for 2 hours was distilled off under reduced pressure, and water was added to the residue The mixture was extracted with dichloromethane The extract was dried over anhydrous sodium sulfate Then, the solvent was distilled off

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

Procedure: To dimethoxyethane (100 mL) was added 4-chlorobenzylbromide (4.1 g), 4-chlorobenzoylchloride (2.56 mL), bis(triphenylphosphine)palladium dichloride (702 mg) and zinc powder (2.6 g) and the mixture was stirred for 2 hours under nitrogen gas atmosphere. The reaction mixture was filtered and the filtrate was concentrated in vacuo and extracted with ethyl acetate. The organic layer was washed with saturated brine, dried over magnesium sulfate and filtered. The filtrate was concentrated in vacuo and the resultant crude product was purified by column chromatography on silica gel (solvent: hexane/ethyl acetate=49/1 to 9/1) to obtain (4-chlorobenzyl) (4-chlorophenyl)methanone (4.85 g, yield: 91%) as a powder. The reaction mixture was filtered the filtrate was concentrated in vacuo extracted with ethyl acetate The organic layer was washed with saturated brine dried over magnesium sulfate filtered The filtrate was concentrated in vacuo the resultant crude product was purified by column chromatography on silica gel (solvent: hexane/ethyl acetate=49/1 to 9/1)

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

Procedure: Bromine (2 ml.) was added dropwise to a solution of p-chloro-2-(p-chlorophenyl)acetophenone (10 g.; 0.038 mole), chloroform (50 ml.) and diethyl ether (25 ml.). The mixture was heated at reflux for 0.5 hours and cooled (ca. 20°). Following a thorough washing with saturated sodium bicarbonate, the organic solution was dried over sodium sulfate and concentrated in vacuo. The residue was chromatographed at low pressure through silica gel 60 mesh (230-400) with 5% ethyl acetate in hexane. Recrystallization from hexane afforded 2.69 g.; m.p. 81.5°-83°. The mixture was heated at reflux for 0.5 hours cooled (ca. 20°) a thorough washing with saturated sodium bicarbonate the organic solution was dried over sodium sulfate concentrated in vacuo The residue was chromatographed at low pressure through silica gel 60 mesh (230-400) with 5% ethyl acetate in hexane Recrystallization from hexane afforded 2.69 g