2-chloro-4-hydrazinylphenol;hydrochloride

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

Procedure: At 0° C., to a mixture of 3-amino-2-chlorophenol 100 g and concentrated hydrochloric acid 250 ml was added slowly aqueous solution 300 ml containing sodium nitrite 67.0 g and followed by addition of water 400 ml. The resulting mixture was stirred for two hours and thereto was added slowly anhydrous tin(II) chloride 292 g and concentrated hydrochloric acid 250 ml and the resulting mixture was stirred for one hour. At room temperature, the resulting mixture was stirred for additional twelve hours, and then the reaction mixture was filtered and was washed with aqueous 10% hydrochloric acid and hexane to give 2-chloro-4-hydrazinophenol hydrochloride salt 105 g. the resulting mixture was stirred for one hour At room temperature, the resulting mixture was stirred for additional twelve hours the reaction mixture was filtered was washed with aqueous 10% hydrochloric acid and hexane

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

Procedure: A mixture of 2-chloro-4-hydrazinophenol hydrochloride salt 3.0 g, 3-methyl-2,4-pentanedione, ethanol 100 ml was stirred with heating under reflux for twelve hours. The solvent was distilled off and thereto was added ethyl acetate 200 ml, and the resulting mixture was stirred for one hour. The precipitates was filtered and was washed with hexane, and was then dried under reduced pressure to give 2-chloro-4-(3,4,5-trimethyl-pyrazol-1-yl)-phenol 3.3 g. with heating under reflux for twelve hours The solvent was distilled off was added ethyl acetate 200 ml the resulting mixture was stirred for one hour The precipitates was filtered was washed with hexane was then dried under reduced pressure

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

Procedure: At 0° C., to a mixture of 3-amino-2-chlorophenol 100 g and concentrated hydrochloric acid 250 ml was added slowly aqueous solution 300 ml containing sodium nitrite 67.0 g and followed by addition of water 400 ml. The resulting mixture was stirred for two hours and thereto was added slowly anhydrous tin(II) chloride 292 g and concentrated hydrochloric acid 250 ml and the resulting mixture was stirred for one hour. At room temperature, the resulting mixture was stirred for additional twelve hours, and then the reaction mixture was filtered and was washed with aqueous 10% hydrochloric acid and hexane to give 2-chloro-4-hydrazinophenol hydrochloride salt 105 g. the resulting mixture was stirred for one hour At room temperature, the resulting mixture was stirred for additional twelve hours the reaction mixture was filtered was washed with aqueous 10% hydrochloric acid and hexane

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

Procedure: A mixture of 2-chloro-4-hydrazinophenol hydrochloride salt 3.0 g, 3-methyl-2,4-pentanedione, ethanol 100 ml was stirred with heating under reflux for twelve hours. The solvent was distilled off and thereto was added ethyl acetate 200 ml, and the resulting mixture was stirred for one hour. The precipitates was filtered and was washed with hexane, and was then dried under reduced pressure to give 2-chloro-4-(3,4,5-trimethyl-pyrazol-1-yl)-phenol 3.3 g. with heating under reflux for twelve hours The solvent was distilled off was added ethyl acetate 200 ml the resulting mixture was stirred for one hour The precipitates was filtered was washed with hexane was then dried under reduced pressure