2,3-difluoro-4-phenyldiazenylphenol

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

Procedure: 61 g (0.26 mol) of 2,3-difluoro-4-(phenyldiazenyl)phenol from Example 3 and 1 g of Pd/C (10%) are initially charged in 800 ml of ethanol. The solution was degassed and aerated with hydrogen. The mixture was stirred at room temperature under a 1 bar hydrogen atmosphere for 18 hours. On completion of hydrogen uptake, the catalyst was filtered off and the filtrate was concentrated on a rotary evaporator, in the course of which the product already crystallized out. The resulting solid was filtered off, washed with a little cold ethanol and dried under high vacuum for 4 hours. 28 g (74%) of the desired compound were obtained as a light brown powder. The solution was degassed On completion of hydrogen uptake, the catalyst was filtered off the filtrate was concentrated on a rotary evaporator, in the course of which the product already crystallized out The resulting solid was filtered off washed with a little cold ethanol dried under high vacuum for 4 hours

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

Procedure: At room temperature, 3.5 g (0.015 mol) of (2,3-difluoro-4-hydroxyphenyl)-phenyldiazene are dissolved in 30 ml of methanol in a 100 ml three-neck flask fitted with internal thermometer, stirrer and gas inlet tube. The flask is flushed with argon, and 1.5 g of Raney nickel and 25 μl of bis(2-hydroxyethyl) sulphide are then added. 692 ml of hydrogen (0.03 mol) are then applied at room temperature with a pressure of about 1 bar. The reaction mixture is admixed with activated charcoal, stirred for a further 15 minutes and filtered over a bed of silica gel. The solvent is distilled off and the residue is washed with n-hexane, affording 2.0 g (91.9% of theory) of 4-hydroxy-2,3-difluoroaniline. fitted with internal thermometer, stirrer and gas inlet tube The flask is flushed with argon, and 1.5 g of Raney nickel and 25 μl of bis(2-hydroxyethyl) sulphide are then added are then applied at room temperature with a pressure of about 1 bar filtered over a bed of silica gel The solvent is distilled off the residue is washed with n-hexane

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

Procedure: 61 g (0.26 mol) of 2,3-difluoro-4-(phenyldiazenyl)phenol from Example 3 and 1 g of Pd/C (10%) are initially charged in 800 ml of ethanol. The solution was degassed and aerated with hydrogen. The mixture was stirred at room temperature under a 1 bar hydrogen atmosphere for 18 hours. On completion of hydrogen uptake, the catalyst was filtered off and the filtrate was concentrated on a rotary evaporator, in the course of which the product already crystallized out. The resulting solid was filtered off, washed with a little cold ethanol and dried under high vacuum for 4 hours. 28 g (74%) of the desired compound were obtained as a light brown powder. The solution was degassed On completion of hydrogen uptake, the catalyst was filtered off the filtrate was concentrated on a rotary evaporator, in the course of which the product already crystallized out The resulting solid was filtered off washed with a little cold ethanol dried under high vacuum for 4 hours