2-tert-butyl-4-chlorophenol

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

Procedure: 2.8 g of 2-tert-butyl-4-chlorophenol [J. Amer. Chem. Soc. 78, 4604 (1956)] are heated under reflux with 2.45 g of 50% by weight aqueous glyoxylic acid and 50 mg of p-toluenesulfonic acid in 20 ml of 1,2-dichloroethane for 3¼ hours. A further 2.45 g of 50% by weight aqueous glyoxylic acid are then added and boiling is continued for 18 hours. The reaction mixture is then washed with water, dried over MgSO4 and concentrated by evaporation using a rotary evaporator. Crystallisation of the residue from hexane yields 1.15 g of 7-tert-butyl-5-chloro-3-hydroxy-3H-benzofuran-2-one (melting point: 423-427 K). 1.1 g of that compound are placed in 5 ml of toluene with 1 ml of thionyl chloride and the reaction mixture is then slowly heated to 373 K at such a rate that the evolution of HCl and SO2 remains vigorous yet controllable. The reaction mixture is then stirred at 373 K for a further hour. Approximately 5 ml of liquid are then distilled off in order to remove the excess thionyl chloride. The residue is diluted with 13 ml of toluene and, at room temperature, 0.6 ml of triethylamine is added dropwise thereto. The thick, red reaction mixture is then heated to reflux temperature and boiled for 45 min. After cooling to room temperature, the isoxindigo which has precipitated is filtered off, freed of triethylamine hydrochloride by washing with water and methanol and dried, yielding 0.47 g (46% of the theoretical yield) of 7,7′-di-tert-butyl-5,5′-dichloro-[3,3′]bibenzofuranylidene-2,2′-dione of formula (LIXa). The reaction mixture is then washed with water dried over MgSO4 concentrated by evaporation a rotary evaporator Crystallisation of the residue from hexane

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

Procedure: 2.8 g of 2-tert-butyl-4-chlorophenol [J. Amer. Chem. Soc. 78, 4604 (1956)] are heated under reflux with 2.45 g of 50% by weight aqueous glyoxylic acid and 50 mg of p-toluenesulfonic acid in 20 ml of 1,2-dichloroethane for 3¼ hours. A further 2.45 g of 50% by weight aqueous glyoxylic acid are then added and boiling is continued for 18 hours. The reaction mixture is then washed with water, dried over MgSO4 and concentrated by evaporation using a rotary evaporator. Crystallisation of the residue from hexane yields 1.15 g of 7-tert-butyl-5-chloro-3-hydroxy-3H-benzofuran-2-one (melting point: 423-427 K). 1.1 g of that compound are placed in 5 ml of toluene with 1 ml of thionyl chloride and the reaction mixture is then slowly heated to 373 K at such a rate that the evolution of HCl and SO2 remains vigorous yet controllable. The reaction mixture is then stirred at 373 K for a further hour. Approximately 5 ml of liquid are then distilled off in order to remove the excess thionyl chloride. The residue is diluted with 13 ml of toluene and, at room temperature, 0.6 ml of triethylamine is added dropwise thereto. The thick, red reaction mixture is then heated to reflux temperature and boiled for 45 min. After cooling to room temperature, the isoxindigo which has precipitated is filtered off, freed of triethylamine hydrochloride by washing with water and methanol and dried, yielding 0.47 g (46% of the theoretical yield) of 7,7′-di-tert-butyl-5,5′-dichloro-[3,3′]bibenzofuranylidene-2,2′-dione of formula (LIXa). The reaction mixture is then washed with water dried over MgSO4 concentrated by evaporation a rotary evaporator Crystallisation of the residue from hexane

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

Procedure: 2.8 g of 2-tert-butyl-4-chlorophenol [J. Amer. Chem. Soc. 78, 4604 (1956)] are refluxed for 3¼ h with 2.45 g of 50% aqueous glyoxylic acid and 50 mg of p-toluenesulfonic acid in 20 ml of 1,2-dichloroethane. Thereafter a further 2.45 g of 50% aqueous glyoxylic acid are added to continue refluxing for 18 h. The reaction mixture is then washed with water, dried over MgSO4 and evaporated in a rotary evaporator. Crystallization of the residue from hexane leaves 1.15 g of 7-tert-butyl-5-chloro-3-hydroxy-3H-benzofuran-2-one (melting point: 150-154° C.). to continue refluxing for 18 h The reaction mixture is then washed with water dried over MgSO4 evaporated in a rotary evaporator Crystallization of the residue from hexane

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

Procedure: Treatment of 2-tert-butyl-4-chlorophenol (12.73 g, 0.070 mol) with allyl bromide (10.01 g, 0.083 mol) and potassium carbonate (38.11 g, 0.276 mol) followed by refluxing the resultant allyl ether in mesitylene generally according to the procedure described for Intermediate 8 gave 2-allyl-6-tert-butyl-4-chlorophenol. Treatment of the phenol with 3-chloroperoxybenzoic acid (35.90 g, 0.146 mol, 77%) followed by potassium carbonate (28.18 g, 0.204 mol) generally according to the procedure described for Intermediate 9 provided (±)-(7-tert-butyl-5-chloro-2,3-dihydro-1-benzofuran-2-yl)methanol. Treatment of the alcohol with with p-toluenesulfonyl chloride (10.27 g, 0.054 mol) generally according to the procedure described for Intermediate 10 afforded 13.84 g (51%) (±)-(7-tert-butyl-5-chloro-2,3-dihydro-1-benzofuran-2-yl)methyl 4-methylbenzenesulfonate as a white solid. mp 74-77° C.; Anal. calcd. for C20H23ClO4S C, 60.83; H, 5.87. Found C, 60.79; H, 5.80.

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

Procedure: To a mixture of p-chlorophenol (19.0 g, 147.8 mmol) and tert-butanol (21.9 g, 295.6 mmol) was added concentrated sulfuric acid (15 mL), and the mixture was stirred at room temperature for 2 days. The reaction mixture was poured into ice water (300 mL), and the mixture was extracted with ethyl acetate. The extract was washed with saturated brine, dried over anhydrous magnesium sulfate, and filtered. The filtrate was concentrated under reduced pressure. The residue was purified by silica gel column chromatography (hexane:ethyl acetate 95:5) to give the title compound (14.3 g, yield 54%) as a brown oil. the mixture was extracted with ethyl acetate The extract was washed with saturated brine dried over anhydrous magnesium sulfate filtered The filtrate was concentrated under reduced pressure The residue was purified by silica gel column chromatography (hexane:ethyl acetate 95:5)

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

Procedure: 2.8 g of 2-tert-butyl-4-chlorophenol [J. Amer. Chem. Soc. 78, 4604 (1956)] are heated under reflux with 2.45 g of 50% by weight aqueous glyoxylic acid and 50 mg of p-toluenesulfonic acid in 20 ml of 1,2-dichloroethane for 3¼ hours. A further 2.45 g of 50% by weight aqueous glyoxylic acid are then added and boiling is continued for 18 hours. The reaction mixture is then washed with water, dried over MgSO4 and concentrated by evaporation using a rotary evaporator. Crystallisation of the residue from hexane yields 1.15 g of 7-tert-butyl-5-chloro-3-hydroxy-3H-benzofuran-2-one (melting point : 423-427 K). 1.1 g of that compound are placed in 5 ml of toluene with 1 ml of thionyl chloride and the reaction mixture is then slowly heated to 373 K at such a rate that the evolution of HCl and SO2 remains vigorous yet controllable. The reaction mixture is then stirred at 373 K for a further hour. Approximately 5 ml of liquid are then distilled off in order to remove the excess thionyl chloride. The residue is diluted with 13 ml of toluene and, at room temperature, 0.6 ml of triethylamine is added dropwise thereto. The thick, red reaction mixture is then heated to reflux temperature and boiled for 45 min. After cooling to room temperature, the isoxindigo which has precipitated is filtered off, freed of triethylamine hydrochloride by washing with water and methanol and dried, yielding 0.47 g (46% of the theoretical yield) of 7,7′-di-tert-butyl-5,5′-dichloro-[3,3′]bibenzofuranylidene-2,2′-dione of formula (LIXa). The reaction mixture is then washed with water dried over MgSO4 concentrated by evaporation a rotary evaporator Crystallisation of the residue from hexane

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

Procedure: 2.8 g of 2-tert-butyl-4-chlorophenol [J. Amer. Chem. Soc. 78, 4604 (1956)] are heated under reflux with 2.45 g of 50% by weight aqueous glyoxylic acid and 50 mg of p-toluenesulfonic acid in 20 ml of 1,2-dichloroethane for 3¼ hours. A further 2.45 g of 50% by weight aqueous glyoxylic acid are then added and boiling is continued for 18 hours. The reaction mixture is then washed with water, dried over MgSO4 and concentrated by evaporation using a rotary evaporator. Crystallisation of the residue from hexane yields 1.15 g of 7-tert-butyl-5-chloro-3-hydroxy-3H-benzofuran-2-one (melting point: 423-427 K). 1.1 g of that compound are placed in 5 ml of toluene with 1 ml of thionyl chloride and the reaction mixture is then slowly heated to 373 K at such a rate that the evolution of HCl and SO2 remains vigorous yet controllable. The reaction mixture is then stirred at 373 K for a further hour. Approximately 5 ml of liquid are then distilled off in order to remove the excess thionyl chloride. The residue is diluted with 13 ml of toluene and, at room temperature, 0.6 ml of triethylamine is added dropwise thereto. The thick, red reaction mixture is then heated to reflux temperature and boiled for 45 min. After cooling to room temperature, the isoxindigo which has precipitated is filtered off, freed of triethylamine hydrochloride by washing with water and methanol and dried, yielding 0.47 g (46% of the theoretical yield) of 7,7′-di-tert-butyl-5,5′-dichloro-[3,3′]bibenzofuranylidene-2,2′-dione of formula (LIXa). The reaction mixture is then washed with water dried over MgSO4 concentrated by evaporation a rotary evaporator Crystallisation of the residue from hexane

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

Procedure: 2.8 g of 2-tert-butyl-4-chlorophenol [J. Amer. Chem. Soc. 78, 4604 (1956)] are refluxed for 3¼ h with 2.45 g of 50% aqueous glyoxylic acid and 50 mg of p-toluenesulfonic acid in 20 ml of 1,2-dichloroethane. Thereafter a further 2.45 g of 50% aqueous glyoxylic acid are added to continue refluxing for 18 h. The reaction mixture is then washed with water, dried over MgSO4 and evaporated in a rotary evaporator. Crystallization of the residue from hexane leaves 1.15 g of 7-tert-butyl-5-chloro-3-hydroxy-3H-benzofuran-2-one (melting point: 150-154° C.). to continue refluxing for 18 h The reaction mixture is then washed with water dried over MgSO4 evaporated in a rotary evaporator Crystallization of the residue from hexane