1,8-dichloroanthracene

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

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

Procedure: 25 g (91 mmol) of 1,8-dichloroanthraquinone and 65 g (1 mol) of Zn dust were suspended in 1 l of a 20% strength by weight aqueous ammonia solution and the mixture was refluxed for 3 hours. After cooling to room temperature, the solid was separated off via a Büchner funnel. The aqueous phase was extracted three times with 150 ml each time of dichloromethane; the solid was extracted a number of times with dichloromethane while being treated with ultrasound. The combined organic phases were dried over magnesium sulfate and freed of the solvent on a rotary evaporator. The solid, whitish yellow residue was suspended in 600 ml of propanol and 65 ml of 12M hydrochloric acid and the mixture was refluxed for three hours. The solvent was subsequently removed under reduced pressure, the residue was taken up in dichloromethane, the solution was washed with saturated sodium hydrogen carbonate solution and dried over magnesium sulfate. Removal of the solvent gave 1,8-dichloroanthracene as a yellow solid which was recrystallized from propanol. the mixture was refluxed for 3 hours the solid was separated off via a Büchner funnel The aqueous phase was extracted three times with 150 ml each time of dichloromethane the solid was extracted a number of times with dichloromethane while being treated with ultrasound The combined organic phases were dried over magnesium sulfate freed of the solvent on a rotary evaporator 65 ml of 12M hydrochloric acid and the mixture was refluxed for three hours The solvent was subsequently removed under reduced pressure the solution was washed with saturated sodium hydrogen carbonate solution dried over magnesium sulfate Removal of the solvent

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

Procedure: 1,8-Dichloroanthracene prepared by the method of H. O. House et al. (J. Org. Chem. 38 1167 (1973)). A 3 L 3-neck flask fitted with overhead mechanical stirrer, thermometer, condenser, and N2 line was charged with 1,8-dichloroanthracene (17.3 g, 70 mmol) and CH2Cl2 (1500 mL). After further cooling with a salt-ice bath to 5°, SnCl4 (Aldrich, 98%, 36.5 g, 0.14 mol, 16.4 mL), was added in one portion to the reaction. No temperature change occurred. The pot temperature was kept below 5°, and 1,1-dichloromethylmethylether (Aldrich, 16.09 g, 0.14 mol, 12.60 mL) was added dropwise over 1 h. The resulting suspension was warmed slowly to reflux (37°). Considerable HCl gas evolution occurred during the warming and the early part of the reaction at 37°. The reaction mixture was then cooled to 10° and hydrolysed by careful addition of 1 L of cold H2O. After 4 h the layers were separated and the organic layer filtered, dried with anhydrous Na2SO4 (Mallinckrodt, 100 g) and filtered again and the volume reduced to 100 mL. The clear yellow solution was passed through a 1000 g plug of SiO2 using PhCH3 as the eluting solvent with 500 mL fractions. This chromatography separated unreacted 1,8-dichloroanthracene (11 g, 63%) from the aldehyde and a more polar product. Fractions containing the aldehyde were combined and the PhCH3 removed, to give 5.83 g (21%) of 4,5-dichloro-9-anthracenecarbaldehyde mp 218°-220°, (PhCH3 /CH3OH), (C,H,Cl), (lit. 224°-226°, E. L. Stogryn, J. Med. Chem. 17 563 (1974)). A 3 L 3-neck flask fitted with overhead mechanical stirrer After further cooling with a salt-ice bath to 5° was kept below 5° The resulting suspension was warmed slowly to reflux (37°) the early part of the reaction at 37° After 4 h the layers were separated the organic layer filtered dried with anhydrous Na2SO4 (Mallinckrodt, 100 g) filtered again This chromatography separated unreacted 1,8-dichloroanthracene (11 g, 63%) from the aldehyde Fractions containing the aldehyde the PhCH3 removed

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

Procedure: A suspension of 1,8-dichloroanthraquinone 1 (10.0 g, 36.1 mmol) and Zinc dust (50.0 g, 765 mmol) in 200 ml of aqueous 28% NH3 was stirred for 3 h at 100° C. After cooling to room temperature, the resulting solid was separated by suction filtration. A CH2Cl2 solution of the resulting crude solid was combined with the CH2Cl2 extract of the supernatant liquid, and the mixture was dried over MgSO4 and concentrated under vacuo. The residual crude solid was dissolved in a mixture of 500 ml of isopropanol and 50 ml of 12 M HCl. After the resulting solution had been refluxed for 3 h, it was concentrated and partitioned between CH2Cl2 and 5% NaHCO3. The organic layer was collected and dried over MgSO4. The solvent was evaporated, and the crude solid product was recrystallized from a CH2Cl2-hexane mixture. The collected product was allowed to dry in the air for 24 h to provide 5.5 g (62%) of 1,8-dichloroanthracene 2 as yellow needles: mp 153° C. IR (KBr): ν=1617, 1547, 1438, 1300, 1210, 953, 872, 775, 720, 678; 1H NMR (CDCl3, 400 MHz) δ=7.25-7.88 (m; 6H, ArH), 8.36 (s; 1H, ArH-10), 9.16 (s; 1H, ArH-9); 13C NMR (CDCl3, 400 MHz) δ=120.99, 125.68, 126.04, 127.33, 127.61, 132.63; MS (EI) m/z (%)=246 (100) [M+], 248 (65); HRMS (EI) Calcd. For C14H8Cl2 [M+] 246.0003, Found 246.0001. After cooling to room temperature the resulting solid was separated by suction filtration extract of the supernatant liquid the mixture was dried over MgSO4 concentrated under vacuo The residual crude solid was dissolved in a mixture of 500 ml of isopropanol and 50 ml of 12 M HCl After the resulting solution had been refluxed for 3 h it was concentrated partitioned between CH2Cl2 and 5% NaHCO3 The organic layer was collected dried over MgSO4 The solvent was evaporated the crude solid product was recrystallized from a CH2Cl2-hexane mixture to dry in the air for 24 h

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

Procedure: 1,8-Dichloroanthracene prepared by the method of H. O. House et. al. (J. Org. Chem. 38 1167 (1973)). A 3 L 3-neck flask fitted with overhead mechanical stirrer, thermometer, condenser, and N2 line was charged with 1,8-dichloroanthracene (17.3 g, 70 mmol) and CH2Cl2 (1500 mL). After further cooling with salt-ice bath to 5°, SnCl4 (Aldrich, 98%, 36.5 g, 0.14 mol, 16.4 mL), was added in one portion to the reaction. No temperature change occurred. The pot temperature was kept below 5°, and 1,1-dichloromethylmethylether (Aldrich, 16.09 g, 0.14 mol, 12.60 mL) was added dropwise over 1 h. The resulting suspension was warmed slowly to reflux (37°). Considerable HCl gas evolution occurred during the warming and the early part of the reaction at 37°. The reaction mixture was then cooled to 10° and hydrolysed by careful addition of 1 L of cold H2O. After 4 h the layers were separated and the organic layer filtered, dried with anhydrous Na2SO4 (Mallinckrodt, 100 g) and filtered again and the volume reduced to 100 mL. The clear yellow solution was passed through a 1000 g plug of SiO2 using PhCH3 as the eluting solvent with 500 mL fractions. This chromatography separated unreacted 1,8-dichloroanthracene (11 g, 63%) from the aldehyde and a more polar product. Fractions containing the aldehyde were combined and the PhCH3 removed, to give 5.83 g (21%) of 4,5-dichloro-9-anthracenecarbaldehyde mp 218°-220°, (PhCH3 /CH3OH), (C, H, Cl), (lit. 224°-226°, E. L. Stogryn, J. Med. Chem. 17 563 (1974)). A 3 L 3-neck flask fitted with overhead mechanical stirrer After further cooling with salt-ice bath to 5° was kept below 5° The resulting suspension was warmed slowly to reflux (37°) the early part of the reaction at 37° After 4 h the layers were separated the organic layer filtered dried with anhydrous Na2SO4 (Mallinckrodt, 100 g) filtered again This chromatography separated unreacted 1,8-dichloroanthracene (11 g, 63%) from the aldehyde Fractions containing the aldehyde the PhCH3 removed

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

Procedure: 25 g (91 mmol) of 1,8-dichloroanthraquinone and 65 g (1 mol) of Zn dust were suspended in 1 l of a 20% strength by weight aqueous ammonia solution and the mixture was refluxed for 3 hours. After cooling to room temperature, the solid was separated off via a Büchner funnel. The aqueous phase was extracted three times with 150 ml each time of dichloromethane; the solid was extracted a number of times with dichloromethane while being treated with ultrasound. The combined organic phases were dried over magnesium sulfate and freed of the solvent on a rotary evaporator. The solid, whitish yellow residue was suspended in 600 ml of propanol and 65 ml of 12M hydrochloric acid and the mixture was refluxed for three hours. The solvent was subsequently removed under reduced pressure, the residue was taken up in dichloromethane, the solution was washed with saturated sodium hydrogen carbonate solution and dried over magnesium sulfate. Removal of the solvent gave 1,8-dichloroanthracene as a yellow solid which was recrystallized from propanol. the mixture was refluxed for 3 hours the solid was separated off via a Büchner funnel The aqueous phase was extracted three times with 150 ml each time of dichloromethane the solid was extracted a number of times with dichloromethane while being treated with ultrasound The combined organic phases were dried over magnesium sulfate freed of the solvent on a rotary evaporator 65 ml of 12M hydrochloric acid and the mixture was refluxed for three hours The solvent was subsequently removed under reduced pressure the solution was washed with saturated sodium hydrogen carbonate solution dried over magnesium sulfate Removal of the solvent