3233-32-7

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

Procedure: Acetyl chloride is reacted with hydroquinone to give 4-acetoxy phenol expressed by the formula (16) shown below.

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

Procedure: A mixture of 1.52 g (10 mmol) of 4-acetoxyphenol, 2.22 g (11 mmol) 1,3-dibromopropane, and 2.98 g (21 mmol) of anhydrous potassium carbonate in dimethylformamide was stirred rapidly at room temperature for 4 hours. Ethyl acetate was added, and the salts present were removed by filtration. The solvent was removed under reduced pressure, and the residue chromatographed over silica gel. Elution with 15% ethyl acetate-hexane gave 270 mg of the title compound, which was homogeneous by thin layer chromatography (15% by volume of ethyl acetate/hexane on silica gel plates). the salts present were removed by filtration The solvent was removed under reduced pressure the residue chromatographed over silica gel Elution with 15% ethyl acetate-hexane

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

Procedure: To a solution of 4-hydroxyphenyl acetate (60.8 g), tert-butyl [(1S)-2-hydroxy-1-methylethyl]carbamate (70 g) and triphenylphosphine (105 g) in THF (300 mL) was added dropwise a solution (1.9 M, 210 mL) of diisopropyl azodicarboxylate in toluene at 0° C., and the mixture was stirred at room temperature for 16 hr. The reaction mixture was concentrated under reduced pressure, the residue was suspended in diethyl ether, and the precipitate was removed by filtration. The filtrate was concentrated, and the residue was purified by silica gel chromatography (hexane/ethyl acetate), and then by silica gel chromatography (NH, hexane/ethyl acetate) to give the title compound (70.9 g). The reaction mixture was concentrated under reduced pressure the precipitate was removed by filtration The filtrate was concentrated the residue was purified by silica gel chromatography (hexane/ethyl acetate)

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

Procedure: To a solution of 4-hydroxyphenyl acetate (60.8 g), tert-butyl [(1S)-2-hydroxy-1-methylethyl]carbamate (70 g) and triphenylphosphine (105 g) in THF (300 mL) was added dropwise a solution (1.9 M, 210 mL) of diisopropyl azodicarboxylate in toluene at 0° C., and the mixture was stirred at room temperature for 16 hr. The reaction mixture was concentrated under reduced pressure, the residue was suspended in diethyl ether, and the precipitate was removed by filtration. The filtrate was concentrated, and the residue was purified by silica gel chromatography (hexane/ethyl acetate), and then by silica gel chromatography (NH, hexane/ethyl acetate) to give the title compound (70.9 g). The reaction mixture was concentrated under reduced pressure the precipitate was removed by filtration The filtrate was concentrated the residue was purified by silica gel chromatography (hexane/ethyl acetate)

Conditions: temp:120.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: 2.35 g of anhydrous potassium carbonate are added to a solution of 2.80 g of 4-biphenylmethyl bromide and 1.72 g of 4-hydroxyphenyl acetate in 75 ml of butyronitrile, and the reaction mixture is stirred at 120° C. overnight. It is filtered with suction, washed with acetonitrile, and concentrated. The residue is taken up in ethyl acetate, washed with water and saturated sodium chloride solution, dried over sodium sulphate and filtered, and the solvent is removed in a rotary evaporator. This is followed by stirring with ethyl acetate, filtration with suction and washing of the resulting crystals several times with ethyl acetate. 1.36 g of product are obtained. A further 0.36 g of product can be isolated from the mother liquor after concentration and chromatography on silica gel with dichloromethane. It is filtered with suction washed with acetonitrile concentrated washed with water and saturated sodium chloride solution dried over sodium sulphate filtered the solvent is removed in a rotary evaporator by stirring with ethyl acetate, filtration with suction washing of the resulting crystals several times with ethyl acetate

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

Procedure: To 5 ml of chloroform were added 152 mg of 4-acetoxyphenol, 211 mg of methyl 1-piperazinecarbodithioate and 36 mg of paraformaldehyde. The resulting mixture was refluxed for 4 hours. The mixture was cooled, and tothis was added chloroform. The mixture was then washed with water and a saturated aqueous sodium chloride solution, dried over anhydrous sodium sulfate and placed under reduced pressure to distill of the solvent. The residue was purified by siica gel column chromatography to yield an oil. The oil was crystallized by addition of ethanol. The obtained crystals were collected by filtration to give 224 mg of the desired compound as a white crystalline product, m.p. 124° C., yield 65.9%. The resulting mixture was refluxed for 4 hours The mixture was cooled The mixture was then washed with water a saturated aqueous sodium chloride solution, dried over anhydrous sodium sulfate to distill of the solvent The residue was purified by siica gel column chromatography to yield an oil The oil was crystallized by addition of ethanol The obtained crystals were collected by filtration

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

Procedure: To 5 ml of chloroform were added 152 mg of 4-acetoxyphenol, 211 mg of methyl 1-piperazinecarbodithioate and 36 mg of paraformaldehyde. The resulting mixture was refluxed for 4 hours. The mixture was cooled, and to this was added chloroform. The mixture was then washed with water and a saturated aqueous sodium chloride solution, dried over anhydrous sodium sulfate and placed under reduced pressure to distill of the solvent. The residue was purified by silica gel column chromatography to yield an oil. The oil was crystallized by addition of ethanol. The obtained crystals were collected by filtration to give 224 mg of the desired compound as a white crystalline product, m.p. 124° C., yield 65.9%. The resulting mixture was refluxed for 4 hours The mixture was cooled The mixture was then washed with water a saturated aqueous sodium chloride solution, dried over anhydrous sodium sulfate to distill of the solvent The residue was purified by silica gel column chromatography to yield an oil The oil was crystallized by addition of ethanol The obtained crystals were collected by filtration

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

Procedure: Acetyl chloride is reacted with hydroquinone to give 4-acetoxy phenol expressed by the formula (16) shown below.