(2,3,4-trichlorophenyl)hydrazine

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

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

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

Procedure: 2,3,4-Trichloroaniline (100 g) was dissolved with stirring in glacial acetic acid (875 ml) at 55°-60° C. A solution of sodium nitrite (39.5 g) in concentrated sulphuric acid (300 ml) was then added over 15 minutes at 55°-60° C. to the solution thus obtained. The viscous mixture obtained was cooled to 5°-10° C. and a solution of stannous chloride dihydrate (437 g) in concentrated hydrochloric acid (375 ml) was added at 5°-10° C. over 20 minutes. A fine, off-white solid precipitated. To aid filtration, the mixture was warmed to 60° C., allowed to cool to laboratory temperature and then filtered. The precipitate was washed on the filter with saturated aqueous sodium chloride solution (100 ml). The damp powder thus obtained was added to a stirred mixture of aqueous ammonia (1.3 liters; S.G. 0.880) and ice. The fine slurry which formed was filtered and the precipitate obtained was dried at 80° C., and boiled twice with chloroform (2×1.5 liters). The chloroform extracts were combined and evaporated to dryness to give 2,3,4-trichlorophenylhydrazine (86 g), m.p. 142°-143° C., in the form of a colourless powder. thus obtained The viscous mixture obtained was cooled to 5°-10° C. A fine, off-white solid precipitated filtration to cool to laboratory temperature filtered The precipitate was washed on the filter with saturated aqueous sodium chloride solution (100 ml) The damp powder thus obtained The fine slurry which formed was filtered the precipitate obtained was dried at 80° C. evaporated to dryness

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

Procedure: 2,3,4-Trichloroaniline (100 g) was dissolved with stirring in glacial acetic acid (875 ml) at 55°-60° C. A solution of sodium nitrite (39.5 g) in concentrated sulphuric acid (300 ml) was then added over 15 minutes at 55°-60° C. to the solution thus obtained. The viscous mixture obtained was cooled to 5°-10° C. and a solution of stannous chloride dihydrate (437 g) in concentrated hydrochloric acid (375 ml) was added at 5°-10° C. over 20 minutes. A fine, off-white solid precipitated. To aid filtration, the mixture was warmed to 60° C., allowed to cool to laboratory temperature and then filtered. The precipitate was washed on the filter with saturated aqueous sodium chloride solution (100 ml). The damp powder thus obtained was added to a stirred mixture of aqueous ammonia (1.3 liters; S.G. 0.880) and ice. The fine slurry which formed was filtered and the precipitate obtained was dried at 80° C., and boiled twice with chloroform (2×1.5 liters). The chloroform extracts were combined and evaporated to dryness to give 2,3,4-trichlorophenylhydrazine (86 g), m.p. 142°-143° C., in the form of a colourless powder. thus obtained The viscous mixture obtained was cooled to 5°-10° C. A fine, off-white solid precipitated filtration to cool to laboratory temperature filtered The precipitate was washed on the filter with saturated aqueous sodium chloride solution (100 ml) The damp powder thus obtained The fine slurry which formed was filtered the precipitate obtained was dried at 80° C. evaporated to dryness

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

Procedure: 2,3,4-Trichlorophenylhydrazine (21.15 g) and ethoxymethylenemalononitrile (12.8 g) in ethoxyethanol (100 ml) were heated at reflux for one hour. The solution was then cooled and diluted with water. The sticky solid precipitate thus obtained was crystallized from toluene (48 ml) to give 5-amino-4-cyano-1-(2,3,4-trichlorophenyl)pyrazole (15 g), m.p. 154°-156° C., in the form of off-white crystals. at reflux for one hour The solution was then cooled The sticky solid precipitate thus obtained was crystallized from toluene (48 ml)

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

Procedure: 2,3,4-Trichlorophenylhydrazine (21.15 g) was added in portions to a refluxing solution of ethoxymethylenemalononitrile (12.2 g) in ethanol (100 ml). The solution obtained was then heated at reflux for one hour, cooled and evaporated to dryness. The residue thus obtained was triturated with diethyl ether (100 ml) to give 5-amino-4-cyano-1-(2,3,4-trichlorophenyl)pyrazole (12.6 g), m.p. 158°-160° C., in the form of light brown crystals. The solution obtained was then heated at reflux for one hour cooled evaporated to dryness The residue thus obtained was triturated with diethyl ether (100 ml)

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

Procedure: 2,3,4-Trichloroaniline (100 g) was dissolved with stirring in glacial acetic acid (875 ml) at 55°-60° C. A solution of sodium nitrite (39.5 g) in concentrated sulphuric acid (300 ml) was then added over 15 minutes at 55°-60° C. to the solution thus obtained. The viscous mixture obtained was cooled to 5°-10° C. and a solution of stannous chloride dihydrate (437 g) in concentrated hydrochloric acid (375 ml) was added at 5°-10° C. over 20 minutes. A fine, off-white solid precipitated. To aid filtration, the mixture was warmed to 60° C., allowed to cool to laboratory temperature and then filtered. The precipitate was washed on the filter with saturated aqueous sodium chloride solution (100 ml). The damp powder thus obtained was added to a stirred mixture of aqueous ammonia (1.3 liters; S.G. 0.880) and ice. The fine slurry which formed was filtered and the precipitate obtained was dried at 80° C., and boiled twice with chloroform (2×1.5 liters). The chloroform extracts were combined and evaporated to dryness to give 2,3,4-trichlorophenylhydrazine (86 g), m.p. 142°-143° C., in the form of a colourless powder. thus obtained The viscous mixture obtained was cooled to 5°-10° C. A fine, off-white solid precipitated filtration to cool to laboratory temperature filtered The precipitate was washed on the filter with saturated aqueous sodium chloride solution (100 ml) The damp powder thus obtained The fine slurry which formed was filtered the precipitate obtained was dried at 80° C. evaporated to dryness

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

Procedure: A solution of 15 g of 2,3,4-trichlorophenylhydrazine, 8.7 g of (ethoxymethylene)malononitrile, 100 ml of glacial acetic acid and 50 ml of water was refluxed for 3 hours. The reaction mixture was cooled, poured into ice water and the precipitated solid was collected by filtration and dried. This solid was dissolved in ethyl acetate and the resulting solution was washed twice with saturated sodium bicarbonate, once with 100 ml of water, once with 100 ml of saturated brine and dried over anhydrous magnesium sulfate. The organic phase was evaporated under reduced pressure and the residue was recrystallized from ethanol to give 13.2 g of 5-amino-1-(2,3,4-trichlorophenyl)-1H-pyrazole-4-carbonitrile. Yield 66%. mp=140°-142° C. The reaction mixture was cooled the precipitated solid was collected by filtration dried This solid was dissolved in ethyl acetate the resulting solution was washed twice with saturated sodium bicarbonate, once with 100 ml of water, once with 100 ml of saturated brine dried over anhydrous magnesium sulfate The organic phase was evaporated under reduced pressure the residue was recrystallized from ethanol

Conditions: temp:0.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: Fifty grams of 2,3,4-trichloroaniline was added portionwise to a solution of 200 ml of concentrated hydrochloric acid at approximately 0° C. To the reaction mixture was added 17.6 g of sodium nitrite dissolved in 100 ml of water dropwise over 1 hour. Next, 94.8 g of stannous chloride dissolved in 100 ml of concentrated hydrochloric acid was added dropwise to the reaction mixture over a 1 hour period while maintaining the temperature at approximately 0° C. The reaction mixture was stirred for approximately 1 hour at this temperature and then warmed to room temperature and stirred for 20 additional hours. The precipitated solid was collected by filtration and dried. The collected solid was added to a cold solution of 300 ml of 25% aqueous sodium hydroxide and this solution was stirred at approximately 5° C. for 1 hour. This aqueous solution was then extracted with ether and the organic phase was washed with water and saturated sodium chloride, and finally dried over anhydrous magnesium sulfate. The organic phase was evaporated under reduced pressure and the residue was recrystallized from ethanol to afford 35 g of 2,3,4-trichlorophenylhydrazine. Yield 66%. mp=138°-140° C. was added dropwise to the reaction mixture over a 1 hour period warmed to room temperature stirred for 20 additional hours The precipitated solid was collected by filtration dried The collected solid was added to a cold solution of 300 ml of 25% aqueous sodium hydroxide this solution was stirred at approximately 5° C. for 1 hour This aqueous solution was then extracted with ether the organic phase was washed with water and saturated sodium chloride finally dried over anhydrous magnesium sulfate The organic phase was evaporated under reduced pressure the residue was recrystallized from ethanol