9H-xanthen-9-ol

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:100.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: 9-Hydroxyxanthene (9.9 g, 50 mmol) and ethyl nitroacetate (6.1 mL, 55 mol) are mixed and heated at 100° C. (oil bath) for 1.5 hours. After cooling, a waxy mixture is suspended in 40 mL of absolute alcohol and 40 mL of 1.25 M of ethanolic potassium hydroxide solution is added. The solution is stirred for 45 minutes at room temperature and ethanol is stripped off. The remaining solid is suspended in water and extracted with diethyl ether. The aqueous portion is acidified with 85% phosphoric acid to pH 2 to 3 to give a white suspension which is cooled overnight. The precipitate is collected by filtration and dried in a vacuum oven at 50° C. This gives 9.18 g of the title compound as a white solid; mp 89°-91° C. After cooling extracted with diethyl ether to give a white suspension which is cooled overnight The precipitate is collected by filtration dried in a vacuum oven at 50° C

Conditions: temp:100.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: 9-Hydroxyxanthene (9.9 g, 50 mmol) and ethyl nitroacetate (6.1 mL, 55 mol) are mixed and heated at 100° C. (oil bath) for 1.5 hours. After cooling, a waxy mixture is suspended in 40 mL of absolute alcohol and 40 mL of 1.25 M of ethanolic potassium hydroxide solution is added. The solution is stirred for 45 minutes at room temperature and ethanol is stripped off. The remaining solid is suspended in water and extracted with diethyl ether. The aqueous portion is acidified with 85% phosphoric acid to pH 2 to 3 to give a white suspension which is cooled overnight. The precipitate is collected by filtration and dried in a vacuum oven at 50° C. This gives 9.18 g of the title compound as a white solid; mp 89°-91° C. After cooling extracted with diethyl ether to give a white suspension which is cooled overnight The precipitate is collected by filtration dried in a vacuum oven at 50° C

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

Procedure: Acetic acid (20 ml) was added to a stirred suspension of 9-hydroxyxanthene (3.96 g, 20 mmol) and ethyl 3-oxo-3-[3-(phenacylmethyloxycarbonyl) cyclobutyl]propanate (6.0 g, 18 mmol) in ethanol (20 ml) at room temperature. A clear solution formed and was allowed to stand for 7 days at room temperature. A clear solution formed

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

Procedure: Acetic acid (20 ml) was added to a stirred suspension of 9-hydroxyxanthene (3.96 g, 20 mmol) and ethyl 3-oxo-3-[3-(phenacylmethyloxycarbonyl) cyclobutyl]propanate (6.0 g, 18 mmol) in ethanol (20 ml) at room temperature. A clear solution formed and was allowed to stand for 7 days at room temperature. A clear solution formed

Conditions: temp:60.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: 17.5 g (0.268 mol) of potassium cyanide are added in portions to a solution, heated at 50° C., of 24.2g (0.122 mol) of xanthydrol in 420 ml of acetic acid. The reaction mixture is subsequently stirred at 60° C. for 2 hours and then cooled, poured onto 400 ml of water and extracted with ethyl acetate/hexane=1:1. The organic phases are washed with water, combined, dried over sodium sulfate and concentrated on a vacuum rotary evaporator. Chromatography of the residue over silica gel using the mobile phase system hexane/ethyl acetate=19:1 and crystallization of the pure fractions from ether/petroleum ether gives 20.2 g (80%) of 9-cyano-xanthene, melting point 101° C. (compound (102), Table 1). The compounds (111), (112), (113), (114), (115), (116) and (117) are prepared analogously to Example 2 from the corresponding substituted xanthydrols and thioxanthydrols, such as, for example, 4-cyclohexyl-xanthydrol, 2-tert-butyl-xanthydrol, 2-nonyl-xanthydrol, 2-(α,α-dimethylbenzyl)-4-methyl-xanthydrol, 2-n-propoxy-xanthydrol, 2,4-diethylthioxanthydrol or 2-dodecyl-thioxanthydrol. cooled extracted with ethyl acetate/hexane=1:1 The organic phases are washed with water dried over sodium sulfate concentrated on a vacuum rotary evaporator Chromatography of the residue over silica gel using the mobile phase system hexane/ethyl acetate=19:1 and crystallization of the pure fractions from ether/petroleum ether

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

Procedure: A solution of ethyl 4-bromobenzoylacetate (14.8 g, 0.05 mol) and 9-hydroxyxanthene (10.9 g, 0.06 mol) in ethanol-acetic acid (1:1, 150 ml) was stirred as described in Example 3 (ii) and a white solid collected. The filtrate was stirred a further 3 days and a second crop collected to give ethyl 2-(4-bromobenzoyl)-2-(9H-xanthen-9-yl)acetate. a white solid collected a second crop collected

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

Procedure: A solution of ethyl 2-methyl-4-bromobenzoylacetate (18.5 g, 65.0 mmol) was heated at 60° C. with 9-hydroxyxanthene (14.2 g, 71.5 mmol) in ethanol-acetic acid (1:1, 200 ml) for 40 h. The product was isolated as in Example 1 (iii), except the aqueous phase was extracted with diethyl ether. The crude product was purified on flash silica eluting with hexane-dichloromethane (3:2 then 1:1) to give ethyl 2-(4-bromo-2-methylbenzoyl)-2-(9H-xanthen-9-yl)acetate as an oil. was extracted with diethyl ether The crude product was purified on flash silica eluting with hexane-dichloromethane (3:2

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

Procedure: A solution of ethyl 2-methyl-4-bromobenzoylacetate (18.5 g, 65.0 mmol) was heated at 60° C. with 9-hydroxyxanthene (14.2 g, 71.5 mmol) in ethanol-acetic acid (1:1, 200 ml) for 40 h. The product was isolated as in Example 1 (iii), except the aqueous phase was extracted with diethyl ether. The crude product was purified on flash silica eluting with hexane-dichloromethane (3:2 then 1:1) to give ethyl 2-(4-bromo-2-methylbenzoyl)-2-(9H-xanthen-9-yl)acetate as an oil. was extracted with diethyl ether The crude product was purified on flash silica eluting with hexane-dichloromethane (3:2

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

Procedure: To a stirred solution of ethyl 3-methoxy-4-methoxycarbonylbenzoylacetate (4.1 g, 14.6 mmol) in a mixture of ethanol (30 ml) and acetic acid (30 ml) was added portionwise 9-hydroxyxanthene (3.2 g, 16.1 mmol). After stirring for 2 weeks at room temperature, the solution was concentrated in vacuo, diluted with water and extracted with dichloromethane (2×). The combined extracts were washed with a saturated solution of sodium bicarbonate, water and dried over magnesium sulphate. Filtration and evaporation gave ethyl 2-(9H-xanthen-9-yl)-2-(3-methoxy-4-methoxycarbonyl-benzoyl)acetate as an oil. the solution was concentrated in vacuo diluted with water extracted with dichloromethane (2×) The combined extracts were washed with a saturated solution of sodium bicarbonate, water dried over magnesium sulphate Filtration and evaporation

Conditions: temp:100.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: 9-Hydroxyxanthene (9.9 g, 50 mmol) and ethyl nitroacetate (6.1 mL, 55 mol) are mixed and heated at 100° C. (oil bath) for 1.5 hours. After cooling, a waxy mixture is suspended in 40 mL of absolute alcohol and 40 mL of 1.25 M of ethanolic potassium hydroxide solution is added. The solution is stirred for 45 minutes at room temperature and ethanol is stripped off. The remaining solid is suspended in water and extracted with diethyl ether. The aqueous portion is acidified with 85% phosphoric acid to pH 2 to 3 to give a white suspension which is cooled overnight. The precipitate is collected by filtration and dried in a vacuum oven at 50° C. This gives 9.18 g of the title compound as a white solid; mp 89°-91° C. After cooling extracted with diethyl ether to give a white suspension which is cooled overnight The precipitate is collected by filtration dried in a vacuum oven at 50° C

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

Procedure: A sample of 0.61 g of cysteine (5 mmole) was suspended in 100 ml of 1,2-dimethoxyethane and 2 ml of TFA. The suspension was stirred under nitrogen gas at room temperature until the solution became clear. To this clear solution was added 1 g of 9H-xanthen-9-ol (5.1 mmole) in one portion. The reaction mixture was stirred at room temperature for 30 minutes and was then neutralized to pH 7 by the addition of a saturated aqueous Na2CO3 solution. The mixture was then concentrated by rotary evaporation. The residue was diluted with 50 ml of water. The aqueous solution was treated with 10% aqueous citric acid solution to adjust the pH to 6. The mixture was stirred at room temperature for 1 hr. The resultant white solid was collected by filtration and was washed with 3×10 ml of water and 3×10 ml of ethyl acetate. The product was dried to yield 1.30 g of product. The reaction mixture was stirred at room temperature for 30 minutes The mixture was then concentrated by rotary evaporation The residue was diluted with 50 ml of water The aqueous solution was treated with 10% aqueous citric acid solution The mixture was stirred at room temperature for 1 hr The resultant white solid was collected by filtration was washed with 3×10 ml of water and 3×10 ml of ethyl acetate The product was dried