4-bromo-2,5-dichlorophenol

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

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

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

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

Procedure: To a solution of 1.25 g (6.734 mmol) 4-chloro-6-methyl-nicotinic acid methyl ester (commercially available, CAS RN 886372-05-0) in 30 mL o-xylene was added 1.792 g (7.408 mmol) 4-bromo-2,5-dichlorophenol (commercially available, CAS RN 1940-42-7), 0.502 g (1.347 mmol) tetrakis(acetonitrile)copper (I) hexafluorophosphate (commercially available, CAS RN 64443-05-6) and 5.536 g (16.836 mmol) cesium carbonate. The reaction mixture was stirred at 120° C. for 20 hours and was then allowed to cool to room temperature. Ethyl acetate (50 mL) and water (50 mL) was added and stirring was continued for another 10 minutes. The reaction mixture was filtered over Dicalite® speed plus (Acros) and the layers were separated. The aqueous layer was extracted with 200 mL ethyl acetate and the combined organic layers were washed with 200 mL brine, dried over magnesium sulfate, filtered and concentrated under vacuum. The residue was purified by silica gel chromatography using a MPLC system (50 g silica gel column, CombiFlash Companion, Isco Inc.) and a gradient of n-heptane:ethyl acetate (100:0 to 40:60) to give 200 mg (8%) of the title compound as a light yellow solid. MS (Turbo Spray): m/z=391.9 [M+H]+. to cool to room temperature stirring was continued for another 10 minutes The reaction mixture was filtered over Dicalite® speed plus (Acros) the layers were separated The aqueous layer was extracted with 200 mL ethyl acetate the combined organic layers were washed with 200 mL brine dried over magnesium sulfate filtered concentrated under vacuum The residue was purified by silica gel chromatography

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

Procedure: To a stirred suspension of 6.0 g (38.08 mmol) 4-chloronicotinic acid (commercially available; CAS RN 10177-29-4) in 200 mL o-xylene were added 10.13 g (41.89 mmol) 4-bromo-2,5-dichlorophenol (commercially available; CAS RN 1940-42-7) and 2.84 g (7.62 mmol) tetrakis-(acetonitrile)-copper hexafluorophosphate (commercially available; CAS RN 64443-05-6). Then 31.31 g (95.20 mmol) cesium carbonate were added and the resulting dark brown suspension as heated to 120° C. for 16 hours. After cooling to room temperature, the sovent was evaporated, the residue dissolved in 1.25 l water, extracted four times with 250 mL ethyl acetate and filtered. The pH of the green filtrate was adjusted to 6 using 25% aqueous hydrochloric acid. The formed precipitate was filtered off to give a first batch of the desired compound. The pH of the filtrate was adjusted to pH 3 using 25% aqueous hydrochloric acid, the suspension stirred for 0.25 hours at room temperature and then kept in the fridge for 64 hours. The suspension was filtered and washed with water to yield another batch of compound. Brown solid (overall yield 5.63 g (41%)). MS (ESI): m/z=363.9 [M+H]+. After cooling to room temperature the sovent was evaporated the residue dissolved in 1.25 l water extracted four times with 250 mL ethyl acetate filtered The formed precipitate was filtered off

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

Procedure: 2,5-Dichloro-4-bromo-phenol was hydroxymethylated in alkaline aqueous solution with excess formalin at 40°C, using a procedure analogous to that described in U.S. Pat. No. 2,631,169 to produce 2-hydroxy-3,6-dichloro-5-bromo-benzyl alcohol.

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

Procedure: 2,5-Dichloro-4-bromo-phenol was hydroxymethylated in alkaline aqueous solution with excess formalin at 40°C, using a procedure analogous to that described in U.S. Pat. No. 2,631,169 to produce 2-hydroxy-3,6-dichloro-5-bromo-benzyl alcohol.

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

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

Procedure: To a solution of 1.25 g (6.734 mmol) 4-chloro-6-methyl-nicotinic acid methyl ester (commercially available, CAS RN 886372-05-0) in 30 mL o-xylene was added 1.792 g (7.408 mmol) 4-bromo-2,5-dichlorophenol (commercially available, CAS RN 1940-42-7), 0.502 g (1.347 mmol) tetrakis(acetonitrile)copper (I) hexafluorophosphate (commercially available, CAS RN 64443-05-6) and 5.536 g (16.836 mmol) cesium carbonate. The reaction mixture was stirred at 120° C. for 20 hours and was then allowed to cool to room temperature. Ethyl acetate (50 mL) and water (50 mL) was added and stirring was continued for another 10 minutes. The reaction mixture was filtered over Dicalite® speed plus (Acros) and the layers were separated. The aqueous layer was extracted with 200 mL ethyl acetate and the combined organic layers were washed with 200 mL brine, dried over magnesium sulfate, filtered and concentrated under vacuum. The residue was purified by silica gel chromatography using a MPLC system (50 g silica gel column, CombiFlash Companion, Isco Inc.) and a gradient of n-heptane:ethyl acetate (100:0 to 40:60) to give 200 mg (8%) of the title compound as a light yellow solid. MS (Turbo Spray): m/z=391.9 [M+H]+. to cool to room temperature stirring was continued for another 10 minutes The reaction mixture was filtered over Dicalite® speed plus (Acros) the layers were separated The aqueous layer was extracted with 200 mL ethyl acetate the combined organic layers were washed with 200 mL brine dried over magnesium sulfate filtered concentrated under vacuum The residue was purified by silica gel chromatography

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

Procedure: To a stirred suspension of 6.0 g (38.08 mmol) 4-chloronicotinic acid (commercially available; CAS RN 10177-29-4) in 200 mL o-xylene were added 10.13 g (41.89 mmol) 4-bromo-2,5-dichlorophenol (commercially available; CAS RN 1940-42-7) and 2.84 g (7.62 mmol) tetrakis-(acetonitrile)-copper hexafluorophosphate (commercially available; CAS RN 64443-05-6). Then 31.31 g (95.20 mmol) cesium carbonate were added and the resulting dark brown suspension as heated to 120° C. for 16 hours. After cooling to room temperature, the solvent was evaporated, the residue dissolved in 1.25 l water, extracted four times with 250 mL ethyl acetate and filtered. The pH of the green filtrate was adjusted to 6 using 25% aqueous hydrochloric acid. The formed precipitate was filtered off to give a first batch of the desired compound. The pH of the filtrate was adjusted to pH 3 using 25% aqueous hydrochloric acid, the suspension stirred for 0.25 hours at room temperature and then kept in the fridge for 64 hours. The suspension was filtered and washed with water to yield another batch of compound. Brown solid (overall yield 5.63 g (41%)). MS (ESI): m/z=363.9 [M+H]+. After cooling to room temperature the solvent was evaporated the residue dissolved in 1.25 l water extracted four times with 250 mL ethyl acetate filtered The formed precipitate was filtered off

Conditions: temp:50.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: Methyl iodide (1.861 mL, 29.76 mmol) was added to a stirred suspension of 4-bromo-2,5-dichlorophenol (4.8 g, 19.84 mmol) and potassium carbonate (8.23 g, 59.53 mmol) in DMF (20 mL) at ambient temperature under air. The resulting suspension was stirred at 50° C. for 90 minutes. The reaction mixture was allowed to cool and diluted with EtOAc (200 mL), and washed sequentially with saturated brine (2×150 mL) and water (100 mL). The organic layer was dried over MgSO4, filtered and evaporated to afford crude product. The crude product was purified by flash silica chromatography, elution gradient 0 to 20% EtOAc in isohexane. Pure fractions were evaporated to dryness to afford 1-bromo-2,5-dichloro-4-methoxybenzene (3.82 g, 75%) as a brown solid. to cool washed sequentially with saturated brine (2×150 mL) and water (100 mL) The organic layer was dried over MgSO4 filtered evaporated to afford crude product The crude product was purified by flash silica chromatography, elution gradient 0 to 20% EtOAc in isohexane Pure fractions were evaporated to dryness

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

Procedure: A mixture of 28.4 gm of 4,5-dichloro-2-nitro-1-phenoxy-benzene, 24.2 gm of 2,5-dichloro-4-bromo-phenol, 10 ml of 10 N sodium hydroxide and 80 ml of dimethylsulfoxide was stirred for 5 hours at 100° C. Thereafter, the reaction mixture was stirred into 700 ml of 1 N sodium hydroxide, the mixture was allowed to stand overnight at room temperature, the liquid phase was decanted, and the precipitated product was taken up in chloroform. The chloroform solution was washed with water, dried with sodium sulfate and evaporated, and the residue was recrystallized from a mixture of 200 ml ethanol and 2 ml dimethylformamide. 36.5 gm (75% of theory) of the light yellow crystalline title compound, m.p. 85° C., were obtained. to stand overnight at room temperature the liquid phase was decanted The chloroform solution was washed with water dried with sodium sulfate evaporated the residue was recrystallized from a mixture of 200 ml ethanol and 2 ml dimethylformamide